7904e521b2
This wires up support for resetting NVRAM for all APIs that allow this feature. Reviewed-by: Ján Tomko <jtomko@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
268 KiB
virsh
management user interface
- Manual section
1
- Manual group
Virtualization Support
- depth
2
SYNOPSIS
virsh [OPTION]... [COMMAND_STRING]
virsh [OPTION]... COMMAND [ARG]...
DESCRIPTION
The virsh program is the main interface for managing virsh guest domains. The program can be used to create, pause, and shutdown domains. It can also be used to list current domains. Libvirt is a C toolkit to interact with the virtualization capabilities of recent versions of Linux (and other OSes). It is free software available under the GNU Lesser General Public License. Virtualization of the Linux Operating System means the ability to run multiple instances of Operating Systems concurrently on a single hardware system where the basic resources are driven by a Linux instance. The library aims at providing a long term stable C API. It currently supports Xen, QEMU, KVM, LXC, OpenVZ, VirtualBox and VMware ESX.
The basic structure of most virsh usage is:
virsh [OPTION]... <command> <domain> [ARG]...Where command is one of the commands listed below; domain is the numeric domain id, or the domain name, or the domain UUID; and ARGS are command specific options. There are a few exceptions to this rule in the cases where the command in question acts on all domains, the entire machine, or directly on the xen hypervisor. Those exceptions will be clear for each of those commands. Note: it is permissible to give numeric names to domains, however, doing so will result in a domain that can only be identified by domain id. In other words, if a numeric value is supplied it will be interpreted as a domain id, not as a name. Any command starting with # is treated as a comment and silently ignored, all other unrecognized commands are diagnosed.
The virsh program can be used either to run one COMMAND by giving the command and its arguments on the shell command line, or a COMMAND_STRING which is a single shell argument consisting of multiple COMMAND actions and their arguments joined with whitespace and separated by semicolons or newlines between commands, where unquoted backslash-newline pairs are elided. Within COMMAND_STRING, virsh understands the same single, double, and backslash escapes as the shell, although you must add another layer of shell escaping in creating the single shell argument, and any word starting with unquoted # begins a comment that ends at newline. If no command is given in the command line, virsh will then start a minimal interpreter waiting for your commands, and the quit command will then exit the program.
The virsh program understands the following OPTIONS.
-c, --connect URI
Connect to the specified URI, as if by the connect command, instead of the default connection.
-d, --debug LEVEL
Enable debug messages at integer LEVEL and above. LEVEL can range from 0 to 4 (default). See the documentation of VIRSH_DEBUG environment variable below for the description of each LEVEL.
-e,--escapestring
Set alternative escape sequence for console command. By default, telnet's ^] is used. Allowed characters when using hat notation are: alphabetic character, @, [, ], , ^, _.
-h,--help
Ignore all other arguments, and behave as if the help command were given instead.
-k,--keepalive-intervalINTERVAL
Set an INTERVAL (in seconds) for sending keepalive messages to check whether connection to the server is still alive. Setting the interval to 0 disables client keepalive mechanism.
-K,--keepalive-countCOUNT
Set a number of times keepalive message can be sent without getting an answer from the server without marking the connection dead. There is no effect to this setting in case the INTERVAL is set to 0.
-l,--logFILE
Output logging details to FILE.
-q,--quiet
Avoid extra informational messages.
-r,--readonly
Make the initial connection read-only, as if by the --readonly option of the connect command.
-t,--timing
Output elapsed time information for each command.
-v,--version[=short]
Ignore all other arguments, and prints the version of the libvirt library virsh is coming from
-V,--version=long
Ignore all other arguments, and prints the version of the libvirt library virsh is coming from and which options and driver are compiled in.
NOTES
Most virsh operations rely upon the libvirt library being able to connect to an already running libvirtd service. This can usually be done using the command service libvirtd start.
Most virsh commands require root privileges to run due to the communications channels used to talk to the hypervisor. Running as non root will return an error.
Most virsh commands act synchronously, except maybe shutdown, setvcpus and setmem. In those cases the fact that the virsh program returned, may not mean the action is complete and you must poll periodically to detect that the guest completed the operation.
virsh strives for backward compatibility. Although the help command only lists the preferred usage of a command, if an older version of virsh supported an alternate spelling of a command or option (such as --tunnelled instead of --tunneled), then scripts using that older spelling will continue to work.
Several virsh commands take an optionally scaled integer; if no scale is provided, then the default is listed in the command (for historical reasons, some commands default to bytes, while other commands default to kibibytes). The following case-insensitive suffixes can be used to select a specific scale:
b, byte byte 1
KB kilobyte 1,000
k, KiB kibibyte 1,024
MB megabyte 1,000,000
M, MiB mebibyte 1,048,576
GB gigabyte 1,000,000,000
G, GiB gibibyte 1,073,741,824
TB terabyte 1,000,000,000,000
T, TiB tebibyte 1,099,511,627,776
PB petabyte 1,000,000,000,000,000
P, PiB pebibyte 1,125,899,906,842,624
EB exabyte 1,000,000,000,000,000,000
E, EiB exbibyte 1,152,921,504,606,846,976GENERIC COMMANDS
The following commands are generic i.e. not specific to a domain.
help
Syntax:
help [command-or-group]This lists each of the virsh commands. When used without options, all commands are listed, one per line, grouped into related categories, displaying the keyword for each group.
To display only commands for a specific group, give the keyword for that group as an option. For example:
Example 1:
virsh # help host
Host and Hypervisor (help keyword 'host'):
capabilities capabilities
cpu-models show the CPU models for an architecture
connect (re)connect to hypervisor
freecell NUMA free memory
hostname print the hypervisor hostname
qemu-attach Attach to existing QEMU process
qemu-monitor-command QEMU Monitor Command
qemu-agent-command QEMU Guest Agent Command
sysinfo print the hypervisor sysinfo
uri print the hypervisor canonical URITo display detailed information for a specific command, give its name as the option instead. For example:
Example 2:
virsh # help list
NAME
list - list domains
SYNOPSIS
list [--inactive] [--all]
DESCRIPTION
Returns list of domains.
OPTIONS
--inactive list inactive domains
--all list inactive & active domainsquit, exit
Syntax:
quit
exitquit this interactive terminal
version
Syntax:
version [--daemon]Will print out the major version info about what this built from. If --daemon is specified then the version of the libvirt daemon is included in the output.
Example:
$ virsh version
Compiled against library: libvirt 1.2.3
Using library: libvirt 1.2.3
Using API: QEMU 1.2.3
Running hypervisor: QEMU 2.0.50
$ virsh version --daemon
Compiled against library: libvirt 1.2.3
Using library: libvirt 1.2.3
Using API: QEMU 1.2.3
Running hypervisor: QEMU 2.0.50
Running against daemon: 1.2.6cd
Syntax:
cd [directory]Will change current directory to directory. The default directory for the cd command is the home directory or, if there is no HOME variable in the environment, the root directory.
This command is only available in interactive mode.
pwd
Syntax:
pwdWill print the current directory.
connect
Syntax:
connect [URI] [--readonly](Re)-Connect to the hypervisor. When the shell is first started, this is automatically run with the URI parameter requested by the -c option on the command line. The URI parameter specifies how to connect to the hypervisor. The URI docs https://libvirt.org/uri.html list the values supported, but the most common are:
xen:///system
this is used to connect to the local Xen hypervisor
qemu:///system
connect locally as root to the daemon supervising QEMU and KVM domains
qemu:///session
connect locally as a normal user to his own set of QEMU and KVM domains
lxc:///system
connect to a local linux container
To find the currently used URI, check the uri command documented below.
For remote access see the URI docs https://libvirt.org/uri.html on how to make URIs. The --readonly option allows for read-only connection
uri
Syntax:
uriPrints the hypervisor canonical URI, can be useful in shell mode.
hostname
Syntax:
hostnamePrint the hypervisor hostname.
sysinfo
Syntax:
sysinfoPrint the XML representation of the hypervisor sysinfo, if available.
nodeinfo
Syntax:
nodeinfoReturns basic information about the node, like number and type of CPU, and size of the physical memory. The output corresponds to virNodeInfo structure. Specifically, the "CPU socket(s)" field means number of CPU sockets per NUMA cell. The information libvirt displays is dependent upon what each architecture may provide.
nodecpumap
Syntax:
nodecpumap [--pretty]Displays the node's total number of CPUs, the number of online CPUs and the list of online CPUs.
With --pretty the online CPUs are printed as a range instead of a list.
nodecpustats
Syntax:
nodecpustats [cpu] [--percent]Returns cpu stats of the node. If cpu is specified, this will print the specified cpu statistics only. If --percent is specified, this will print the percentage of each kind of cpu statistics during 1 second.
nodememstats
Syntax:
nodememstats [cell]Returns memory stats of the node. If cell is specified, this will print the specified cell statistics only.
nodesevinfo
Syntax:
nodesevinfoReports information about the AMD SEV launch security features for the node, if any. Some of this information is also reported in the domain capabilities XML document.
nodesuspend
Syntax:
nodesuspend [target] [duration]Puts the node (host machine) into a system-wide sleep state and schedule the node's Real-Time-Clock interrupt to resume the node after the time duration specified by duration is out. target specifies the state to which the host will be suspended to, it can be "mem" (suspend to RAM), "disk" (suspend to disk), or "hybrid" (suspend to both RAM and disk). duration specifies the time duration in seconds for which the host has to be suspended, it should be at least 60 seconds.
node-memory-tune
Syntax:
node-memory-tune [shm-pages-to-scan] [shm-sleep-millisecs] [shm-merge-across-nodes]Allows you to display or set the node memory parameters. shm-pages-to-scan can be used to set the number of pages to scan before the shared memory service goes to sleep; shm-sleep-millisecs can be used to set the number of millisecs the shared memory service should sleep before next scan; shm-merge-across-nodes specifies if pages from different numa nodes can be merged. When set to 0, only pages which physically reside in the memory area of same NUMA node can be merged. When set to 1, pages from all nodes can be merged. Default to 1.
Note: Currently the "shared memory service" only means KSM (Kernel Samepage Merging).
capabilities
Syntax:
capabilitiesPrint an XML document describing the capabilities of the hypervisor we are currently connected to. This includes a section on the host capabilities in terms of CPU and features, and a set of description for each kind of guest which can be virtualized. For a more complete description see:
https://libvirt.org/formatcaps.html
The XML also show the NUMA topology information if available.
domcapabilities
Syntax:
domcapabilities [virttype] [emulatorbin] [arch] [machine]Print an XML document describing the domain capabilities for the hypervisor we are connected to using information either sourced from an existing domain or taken from the virsh capabilities output. This may be useful if you intend to create a new domain and are curious if for instance it could make use of VFIO by creating a domain for the hypervisor with a specific emulator and architecture.
Each hypervisor will have different requirements regarding which options are required and which are optional. A hypervisor can support providing a default value for any of the options.
The virttype option specifies the virtualization type used. The value to be used is either from the 'type' attribute of the <domain/> top level element from the domain XML or the 'type' attribute found within each <guest/> element from the virsh capabilities output. The emulatorbin option specifies the path to the emulator. The value to be used is either the <emulator> element in the domain XML or the virsh capabilities output. The arch option specifies the architecture to be used for the domain. The value to be used is either the "arch" attribute from the domain's XML <os/> element and <type/> subelement or the "name" attribute of an <arch/> element from the virsh capabililites output. The machine specifies the machine type for the emulator. The value to be used is either the "machine" attribute from the domain's XML <os/> element and <type/> subelement or one from a list of machines from the virsh capabilities output for a specific architecture and domain type.
For the QEMU hypervisor, a virttype of either 'qemu' or 'kvm' must be supplied along with either the emulatorbin or arch in order to generate output for the default machine. Supplying a machine value will generate output for the specific machine.
pool-capabilities
Syntax:
pool-capabilitiesPrint an XML document describing the storage pool capabilities for the connected storage driver. This may be useful if you intend to create a new storage pool and need to know the available pool types and supported storage pool source and target volume formats as well as the required source elements to create the pool.
inject-nmi
Syntax:
inject-nmi domainInject NMI to the guest.
list
Syntax:
list [--inactive | --all]
[--managed-save] [--title]
{ [--table] | --name | --uuid | --id }
[--persistent] [--transient]
[--with-managed-save] [--without-managed-save]
[--autostart] [--no-autostart]
[--with-snapshot] [--without-snapshot]
[--with-checkpoint] [--without-checkpoint]
[--state-running] [--state-paused]
[--state-shutoff] [--state-other]Prints information about existing domains. If no options are specified it prints out information about running domains.
Example 1:
An example format for the list is as follows:
``virsh`` list
Id Name State
----------------------------------------------------
0 Domain-0 running
2 fedora pausedName is the name of the domain. ID the domain numeric id. State is the run state (see below).
STATES
The State field lists what state each domain is currently in. A domain can be in one of the following possible states:
runningThe domain is currently running on a CPU
idleThe domain is idle, and not running or runnable. This can be caused because the domain is waiting on IO (a traditional wait state) or has gone to sleep because there was nothing else for it to do.
pausedThe domain has been paused, usually occurring through the administrator running
virsh suspend. When in a paused state the domain will still consume allocated resources like memory, but will not be eligible for scheduling by the hypervisor.in shutdownThe domain is in the process of shutting down, i.e. the guest operating system has been notified and should be in the process of stopping its operations gracefully.
shut offThe domain is not running. Usually this indicates the domain has been shut down completely, or has not been started.
crashedThe domain has crashed, which is always a violent ending. Usually this state can only occur if the domain has been configured not to restart on crash.
pmsuspendedThe domain has been suspended by guest power management, e.g. entered into s3 state.
Normally only active domains are listed. To list inactive domains specify --inactive or --all to list both active and inactive domains.
Filtering
To further filter the list of domains you may specify one or more of filtering flags supported by the list command. These flags are grouped by function. Specifying one or more flags from a group enables the filter group. Note that some combinations of flags may yield no results. Supported filtering flags and groups:
Persistence
Flag --persistent is used to include persistent guests in the returned list. To include transient guests specify --transient.
Existence of managed save image
To list domains having a managed save image specify flag --with-managed-save. For domains that don't have a managed save image specify --without-managed-save.
Domain state
The following filter flags select a domain by its state: --state-running for running domains, --state-paused for paused domains, --state-shutoff for turned off domains and --state-other for all other states as a fallback.
Autostarting domains
To list autostarting domains use the flag --autostart. To list domains with this feature disabled use --no-autostart.
Snapshot existence
Domains that have snapshot images can be listed using flag --with-snapshot, domains without a snapshot --without-snapshot.
Checkpoint existence
Domains that have checkpoints can be listed using flag --with-checkpoint, domains without a checkpoint --without-checkpoint.
When talking to older servers, this command is forced to use a series of API calls with an inherent race, where a domain might not be listed or might appear more than once if it changed state between calls while the list was being collected. Newer servers do not have this problem.
If --managed-save is specified, then domains that have managed save state (only possible if they are in the shut off state, so you need to specify --inactive or --all to actually list them) will instead show as saved in the listing. This flag is usable only with the default --table output. Note that this flag does not filter the list of domains.
If --name is specified, domain names are printed instead of the table formatted one per line. If --uuid is specified domain's UUID's are printed instead of names. If --id is specified then domain's ID's are printed indead of names. However, it is possible to combine --name, --uuid and --id to select only desired fields for printing. Flag --table specifies that the legacy table-formatted output should be used, but it is mutually exclusive with --name, --uuid and --id. This is the default and will be used if neither of --name, --uuid or --id is specified. If neither --name nor --uuid is specified, but --id is, then only active domains are listed, even with the --all parameter as otherwise the output would just contain bunch of lines with just -1.
If --title is specified, then the short domain description (title) is printed in an extra column. This flag is usable only with the default --table output.
Example 2:
$ virsh list --title
Id Name State Title
-------------------------------------------
0 Domain-0 running Mailserver 1
2 fedora pausedfreecell
Syntax:
freecell [{ [--cellno] cellno | --all }]Prints the available amount of memory on the machine or within a NUMA cell. The freecell command can provide one of three different displays of available memory on the machine depending on the options specified. With no options, it displays the total free memory on the machine. With the --all option, it displays the free memory in each cell and the total free memory on the machine. Finally, with a numeric argument or with --cellno plus a cell number it will display the free memory for the specified cell only.
freepages
Syntax:
freepages [{ [--cellno] cellno [--pagesize] pagesize | --all }]Prints the available amount of pages within a NUMA cell. cellno refers to the NUMA cell you're interested in. pagesize is a scaled integer (see NOTES above). Alternatively, if --all is used, info on each possible combination of NUMA cell and page size is printed out.
allocpages
Syntax:
allocpages [--pagesize] pagesize [--pagecount] pagecount [[--cellno] cellno] [--add] [--all]Change the size of pages pool of pagesize on the host. If --add is specified, then pagecount pages are added into the pool. However, if --add wasn't specified, then the pagecount is taken as the new absolute size of the pool (this may be used to free some pages and size the pool down). The cellno modifier can be used to narrow the modification down to a single host NUMA cell. On the other end of spectrum lies --all which executes the modification on all NUMA cells.
cpu-baseline
Syntax:
cpu-baseline FILE [--features] [--migratable]Compute baseline CPU which will be supported by all host CPUs given in <file>. (See hypervisor-cpu-baseline command to get a CPU which can be provided by a specific hypervisor.) The list of host CPUs is built by extracting all <cpu> elements from the <file>. Thus, the <file> can contain either a set of <cpu> elements separated by new lines or even a set of complete <capabilities> elements printed by capabilities command. If --features is specified, then the resulting XML description will explicitly include all features that make up the CPU, without this option features that are part of the CPU model will not be listed in the XML description. If --migratable is specified, features that block migration will not be included in the resulting CPU.
cpu-compare
Syntax:
cpu-compare FILE [--error] [--validate]Compare CPU definition from XML <file> with host CPU. (See hypervisor-cpu-compare command for comparing the CPU definition with the CPU which a specific hypervisor is able to provide on the host.) The XML <file> may contain either host or guest CPU definition. The host CPU definition is the <cpu> element and its contents as printed by capabilities command. The guest CPU definition is the <cpu> element and its contents from domain XML definition or the CPU definition created from the host CPU model found in domain capabilities XML (printed by domcapabilities command). In addition to the <cpu> element itself, this command accepts full domain XML, capabilities XML, or domain capabilities XML containing the CPU definition. For more information on guest CPU definition see: https://libvirt.org/formatdomain.html#elementsCPU. If --error is specified, the command will return an error when the given CPU is incompatible with host CPU and a message providing more details about the incompatibility will be printed out. If --validate is specified, validates the format of the XML document against an internal RNG schema.
cpu-models
Syntax:
cpu-models archPrint the list of CPU models known by libvirt for the specified architecture. Whether a specific hypervisor is able to create a domain which uses any of the printed CPU models is a separate question which can be answered by looking at the domain capabilities XML returned by domcapabilities command. Moreover, for some architectures libvirt does not know any CPU models and the usable CPU models are only limited by the hypervisor. This command will print that all CPU models are accepted for these architectures and the actual list of supported CPU models can be checked in the domain capabilities XML.
hypervisor-cpu-compare
Syntax:
hypervisor-cpu-compare FILE [virttype] [emulator] [arch] [machine] [--error] [--validate]Compare CPU definition from XML <file> with the CPU the hypervisor is able to provide on the host. (This is different from cpu-compare which compares the CPU definition with the host CPU without considering any specific hypervisor and its abilities.)
The XML FILE may contain either a host or guest CPU definition. The host CPU definition is the <cpu> element and its contents as printed by the capabilities command. The guest CPU definition is the <cpu> element and its contents from the domain XML definition or the CPU definition created from the host CPU model found in the domain capabilities XML (printed by the domcapabilities command). In addition to the <cpu> element itself, this command accepts full domain XML, capabilities XML, or domain capabilities XML containing the CPU definition. For more information on guest CPU definition see: https://libvirt.org/formatdomain.html#elementsCPU.
The virttype option specifies the virtualization type (usable in the 'type' attribute of the <domain> top level element from the domain XML). emulator specifies the path to the emulator, arch specifies the CPU architecture, and machine specifies the machine type. If --error is specified, the command will return an error when the given CPU is incompatible with the host CPU and a message providing more details about the incompatibility will be printed out. If --validate is specified, validates the format of the XML document against an internal RNG schema.
hypervisor-cpu-baseline
Syntax:
hypervisor-cpu-baseline FILE [virttype] [emulator] [arch] [machine] [--features] [--migratable]Compute a baseline CPU which will be compatible with all CPUs defined in an XML file and with the CPU the hypervisor is able to provide on the host. (This is different from cpu-baseline which does not consider any hypervisor abilities when computing the baseline CPU.)
The XML FILE may contain either host or guest CPU definitions describing the host CPU model. The host CPU definition is the <cpu> element and its contents as printed by capabilities command. The guest CPU definition may be created from the host CPU model found in domain capabilities XML (printed by domcapabilities command). In addition to the <cpu> elements, this command accepts full capabilities XMLs, or domain capabilities XMLs containing the CPU definitions. It is recommended to use only the CPU definitions from domain capabilities, as on some architectures using the host CPU definition may either fail or provide unexpected results.
When FILE contains only a single CPU definition, the command will print the same CPU with restrictions imposed by the capabilities of the hypervisor. Specifically, running th virsh hypervisor-cpu-baseline command with no additional options on the result of virsh domcapabilities will transform the host CPU model from domain capabilities XML to a form directly usable in domain XML.
The virttype option specifies the virtualization type (usable in the 'type' attribute of the <domain> top level element from the domain XML). emulator specifies the path to the emulator, arch specifies the CPU architecture, and machine specifies the machine type. If --features is specified, then the resulting XML description will explicitly include all features that make up the CPU, without this option features that are part of the CPU model will not be listed in the XML description. If --migratable is specified, features that block migration will not be included in the resulting CPU.
DOMAIN COMMANDS
The following commands manipulate domains directly, as stated previously most commands take domain as the first parameter. The domain can be specified as a short integer, a name or a full UUID.
autostart
Syntax:
autostart [--disable] domainConfigure a domain to be automatically started at boot.
The option --disable disables autostarting.
blkdeviotune
Syntax:
blkdeviotune domain device [[--config] [--live] | [--current]]
[[total-bytes-sec] | [read-bytes-sec] [write-bytes-sec]]
[[total-iops-sec] | [read-iops-sec] [write-iops-sec]]
[[total-bytes-sec-max] | [read-bytes-sec-max] [write-bytes-sec-max]]
[[total-iops-sec-max] | [read-iops-sec-max] [write-iops-sec-max]]
[[total-bytes-sec-max-length] |
[read-bytes-sec-max-length] [write-bytes-sec-max-length]]
[[total-iops-sec-max-length] |
[read-iops-sec-max-length] [write-iops-sec-max-length]]
[size-iops-sec] [group-name]Set or query the block disk io parameters for a block device of domain. device specifies a unique target name (<target dev='name'/>) or source file (<source file='name'/>) for one of the disk devices attached to domain (see also domblklist for listing these names).
If no limit is specified, it will query current I/O limits setting. Otherwise, alter the limits with these flags: --total-bytes-sec specifies total throughput limit as a scaled integer, the default being bytes per second if no suffix is specified. --read-bytes-sec specifies read throughput limit as a scaled integer, the default being bytes per second if no suffix is specified. --write-bytes-sec specifies write throughput limit as a scaled integer, the default being bytes per second if no suffix is specified. --total-iops-sec specifies total I/O operations limit per second. --read-iops-sec specifies read I/O operations limit per second. --write-iops-sec specifies write I/O operations limit per second. --total-bytes-sec-max specifies maximum total throughput limit as a scaled integer, the default being bytes per second if no suffix is specified --read-bytes-sec-max specifies maximum read throughput limit as a scaled integer, the default being bytes per second if no suffix is specified. --write-bytes-sec-max specifies maximum write throughput limit as a scaled integer, the default being bytes per second if no suffix is specified. --total-iops-sec-max specifies maximum total I/O operations limit per second. --read-iops-sec-max specifies maximum read I/O operations limit per second. --write-iops-sec-max specifies maximum write I/O operations limit per second. --total-bytes-sec-max-length specifies duration in seconds to allow maximum total throughput limit. --read-bytes-sec-max-length specifies duration in seconds to allow maximum read throughput limit. --write-bytes-sec-max-length specifies duration in seconds to allow maximum write throughput limit. --total-iops-sec-max-length specifies duration in seconds to allow maximum total I/O operations limit. --read-iops-sec-max-length specifies duration in seconds to allow maximum read I/O operations limit. --write-iops-sec-max-length specifies duration in seconds to allow maximum write I/O operations limit. --size-iops-sec specifies size I/O operations limit per second. --group-name specifies group name to share I/O quota between multiple drives. For a QEMU domain, if no name is provided, then the default is to have a single group for each device.
Older versions of virsh only accepted these options with underscore instead of dash, as in --total_bytes_sec.
Bytes and iops values are independent, but setting only one value (such as --read-bytes-sec) resets the other two in that category to unlimited. An explicit 0 also clears any limit. A non-zero value for a given total cannot be mixed with non-zero values for read or write.
It is up to the hypervisor to determine how to handle the length values. For the QEMU hypervisor, if an I/O limit value or maximum value is set, then the default value of 1 second will be displayed. Supplying a 0 will reset the value back to the default.
If --live is specified, affect a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. When setting the disk io parameters both --live and --config flags may be given, but --current is exclusive. For querying only one of --live, --config or --current can be specified. If no flag is specified, behavior is different depending on hypervisor.
blkiotune
Syntax:
blkiotune domain [--weight weight] [--device-weights device-weights]
[--device-read-iops-sec device-read-iops-sec]
[--device-write-iops-sec device-write-iops-sec]
[--device-read-bytes-sec device-read-bytes-sec]
[--device-write-bytes-sec device-write-bytes-sec]
[[--config] [--live] | [--current]]Display or set the blkio parameters. QEMU/KVM supports --weight. --weight is in range [100, 1000]. After kernel 2.6.39, the value could be in the range [10, 1000].
device-weights is a single string listing one or more device/weight pairs, in the format of /path/to/device,weight,/path/to/device,weight. Each weight is in the range [100, 1000], [10, 1000] after kernel 2.6.39, or the value 0 to remove that device from per-device listings. Only the devices listed in the string are modified; any existing per-device weights for other devices remain unchanged.
device-read-iops-sec is a single string listing one or more device/read_iops_sec pairs, int the format of /path/to/device,read_iops_sec,/path/to/device,read_iops_sec. Each read_iops_sec is a number which type is unsigned int, value 0 to remove that device from per-device listing. Only the devices listed in the string are modified; any existing per-device read_iops_sec for other devices remain unchanged.
device-write-iops-sec is a single string listing one or more device/write_iops_sec pairs, int the format of /path/to/device,write_iops_sec,/path/to/device,write_iops_sec. Each write_iops_sec is a number which type is unsigned int, value 0 to remove that device from per-device listing. Only the devices listed in the string are modified; any existing per-device write_iops_sec for other devices remain unchanged.
device-read-bytes-sec is a single string listing one or more device/read_bytes_sec pairs, int the format of /path/to/device,read_bytes_sec,/path/to/device,read_bytes_sec. Each read_bytes_sec is a number which type is unsigned long long, value 0 to remove that device from per-device listing. Only the devices listed in the string are modified; any existing per-device read_bytes_sec for other devices remain unchanged.
device-write-bytes-sec is a single string listing one or more device/write_bytes_sec pairs, int the format of /path/to/device,write_bytes_sec,/path/to/device,write_bytes_sec. Each write_bytes_sec is a number which type is unsigned long long, value 0 to remove that device from per-device listing. Only the devices listed in the string are modified; any existing per-device write_bytes_sec for other devices remain unchanged.
If --live is specified, affect a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. If no flag is specified, behavior is different depending on hypervisor.
blockcommit
Syntax:
blockcommit domain path [bandwidth] [--bytes] [base]
[--shallow] [top] [--delete] [--keep-relative]
[--wait [--async] [--verbose]] [--timeout seconds]
[--active] [{--pivot | --keep-overlay}]Reduce the length of a backing image chain, by committing changes at the top of the chain (snapshot or delta files) into backing images. By default, this command attempts to flatten the entire chain. If base and/or top are specified as files within the backing chain, then the operation is constrained to committing just that portion of the chain; --shallow can be used instead of base to specify the immediate backing file of the resulting top image to be committed. The files being committed are rendered invalid, possibly as soon as the operation starts; using the --delete flag will attempt to remove these invalidated files at the successful completion of the commit operation. When the --keep-relative flag is used, the backing file paths will be kept relative.
When top is omitted or specified as the active image, it is also possible to specify --active to trigger a two-phase active commit. In the first phase, top is copied into base and the job can only be canceled, with top still containing data not yet in base. In the second phase, top and base remain identical until a call to blockjob with the --abort flag (keeping top as the active image that tracks changes from that point in time) or the --pivot flag (making base the new active image and invalidating top).
By default, this command returns as soon as possible, and data for the entire disk is committed in the background; the progress of the operation can be checked with blockjob. However, if --wait is specified, then this command will block until the operation completes (or for --active, enters the second phase), or until the operation is canceled because the optional timeout in seconds elapses or SIGINT is sent (usually with Ctrl-C). Using --verbose along with --wait will produce periodic status updates. If job cancellation is triggered, --async will return control to the user as fast as possible, otherwise the command may continue to block a little while longer until the job is done cleaning up. Using --pivot is shorthand for combining --active --wait with an automatic blockjob --pivot; and using --keep-overlay is shorthand for combining --active --wait with an automatic blockjob --abort.
path specifies fully-qualified path of the disk; it corresponds to a unique target name (<target dev='name'/>) or source file (<source file='name'/>) for one of the disk devices attached to domain (see also domblklist for listing these names). bandwidth specifies copying bandwidth limit in MiB/s, although for QEMU, it may be non-zero only for an online domain. For further information on the bandwidth argument see the corresponding section for the blockjob command.
blockcopy
Syntax:
blockcopy domain path { dest [format] [--blockdev] | --xml file }
[--shallow] [--reuse-external] [bandwidth]
[--wait [--async] [--verbose]] [{--pivot | --finish}]
[--timeout seconds] [granularity] [buf-size] [--bytes]
[--transient-job] [--synchronous-writes]Copy a disk backing image chain to a destination. Either dest as the destination file name, or --xml with the name of an XML file containing a top-level <disk> element describing the destination, must be present. Additionally, if dest is given, format should be specified to declare the format of the destination (if format is omitted, then libvirt will reuse the format of the source, or with --reuse-external will be forced to probe the destination format, which could be a potential security hole). The command supports --raw as a boolean flag synonym for --format=raw. When using dest, the destination is treated as a regular file unless --blockdev is used to signal that it is a block device. By default, this command flattens the entire chain; but if --shallow is specified, the copy shares the backing chain.
If --reuse-external is specified, then the destination must exist and have sufficient space to hold the copy. If --shallow is used in conjunction with --reuse-external then the pre-created image must have guest visible contents identical to guest visible contents of the backing file of the original image. This may be used to modify the backing file names on the destination.
By default, the copy job runs in the background, and consists of two phases. Initially, the job must copy all data from the source, and during this phase, the job can only be canceled to revert back to the source disk, with no guarantees about the destination. After this phase completes, both the source and the destination remain mirrored until a call to blockjob with the --abort and --pivot flags pivots over to the copy, or a call without --pivot leaves the destination as a faithful copy of that point in time. However, if --wait is specified, then this command will block until the mirroring phase begins, or cancel the operation if the optional timeout in seconds elapses or SIGINT is sent (usually with Ctrl-C). Using --verbose along with --wait will produce periodic status updates. Using --pivot (similar to blockjob --pivot) or --finish (similar to blockjob --abort) implies --wait, and will additionally end the job cleanly rather than leaving things in the mirroring phase. If job cancellation is triggered by timeout or by --finish, --async will return control to the user as fast as possible, otherwise the command may continue to block a little while longer until the job has actually cancelled.
path specifies fully-qualified path of the disk. bandwidth specifies copying bandwidth limit in MiB/s. Specifying a negative value is interpreted as an unsigned long long value that might be essentially unlimited, but more likely would overflow; it is safer to use 0 for that purpose. For further information on the bandwidth argument see the corresponding section for the blockjob command. Specifying granularity allows fine-tuning of the granularity that will be copied when a dirty region is detected; larger values trigger less I/O overhead but may end up copying more data overall (the default value is usually correct); hypervisors may restrict this to be a power of two or fall within a certain range. Specifying buf-size will control how much data can be simultaneously in-flight during the copy; larger values use more memory but may allow faster completion (the default value is usually correct).
--transient-job allows specifying that the user does not require the job to be recovered if the VM crashes or is turned off before the job completes. This flag removes the restriction of copy jobs to transient domains if that restriction is applied by the hypervisor.
If --synchronous-writes is specified the block job will wait for guest writes to be propagated both to the original image and to the destination of the copy so that it's guaranteed that the job converges if the destination storage is slower. This may impact performance of writes while the blockjob is running.
blockjob
Syntax:
blockjob domain path { [--abort] [--async] [--pivot] |
[--info] [--raw] [--bytes] | [bandwidth] }Manage active block operations. There are three mutually-exclusive modes: --info, bandwidth, and --abort. --async and --pivot imply abort mode; --raw implies info mode; and if no mode was given, --info mode is assumed.
path specifies fully-qualified path of the disk; it corresponds to a unique target name (<target dev='name'/>) or source file (<source file='name'/>) for one of the disk devices attached to domain (see also domblklist for listing these names).
In --abort mode, the active job on the specified disk will be aborted. If --async is also specified, this command will return immediately, rather than waiting for the cancellation to complete. If --pivot is specified, this requests that an active copy or active commit job be pivoted over to the new image.
In --info mode, the active job information on the specified disk will be printed. By default, the output is a single human-readable summary line; this format may change in future versions. Adding --raw lists each field of the struct, in a stable format. If the --bytes flag is set, then the command errors out if the server could not supply bytes/s resolution; when omitting the flag, raw output is listed in MiB/s and human-readable output automatically selects the best resolution supported by the server.
bandwidth can be used to set bandwidth limit for the active job in MiB/s. If --bytes is specified then the bandwidth value is interpreted in bytes/s. Specifying a negative value is interpreted as an unsigned long value or essentially unlimited. The hypervisor can choose whether to reject the value or convert it to the maximum value allowed. Optionally a scaled positive number may be used as bandwidth (see NOTES above). Using --bytes with a scaled value permits a finer granularity to be selected. A scaled value used without --bytes will be rounded down to MiB/s. Note that the --bytes may be unsupported by the hypervisor.
Note that the progress reported for blockjobs corresponding to a pull-mode backup don't report progress of the backup but rather usage of temporary space required for the backup.
blockpull
Syntax:
blockpull domain path [bandwidth] [--bytes] [base]
[--wait [--verbose] [--timeout seconds] [--async]]
[--keep-relative]Populate a disk from its backing image chain. By default, this command flattens the entire chain; but if base is specified, containing the name of one of the backing files in the chain, then that file becomes the new backing file and only the intermediate portion of the chain is pulled. Once all requested data from the backing image chain has been pulled, the disk no longer depends on that portion of the backing chain.
By default, this command returns as soon as possible, and data for the entire disk is pulled in the background; the progress of the operation can be checked with blockjob. However, if --wait is specified, then this command will block until the operation completes, or cancel the operation if the optional timeout in seconds elapses or SIGINT is sent (usually with Ctrl-C). Using --verbose along with --wait will produce periodic status updates. If job cancellation is triggered, --async will return control to the user as fast as possible, otherwise the command may continue to block a little while longer until the job is done cleaning up.
Using the --keep-relative flag will keep the backing chain names relative.
path specifies fully-qualified path of the disk; it corresponds to a unique target name (<target dev='name'/>) or source file (<source file='name'/>) for one of the disk devices attached to domain (see also domblklist for listing these names). bandwidth specifies copying bandwidth limit in MiB/s. For further information on the bandwidth argument see the corresponding section for the blockjob command.
blockresize
Syntax:
blockresize domain path sizeResize a block device of domain while the domain is running, path specifies the absolute path of the block device; it corresponds to a unique target name (<target dev='name'/>) or source file (<source file='name'/>) for one of the disk devices attached to domain (see also domblklist for listing these names).
size is a scaled integer (see NOTES above) which defaults to KiB (blocks of 1024 bytes) if there is no suffix. You must use a suffix of "B" to get bytes (note that for historical reasons, this differs from vol-resize which defaults to bytes without a suffix).
console
Syntax:
console domain [devname] [--safe] [--force]Connect the virtual serial console for the guest. The optional devname parameter refers to the device alias of an alternate console, serial or parallel device configured for the guest. If omitted, the primary console will be opened.
If the flag --safe is specified, the connection is only attempted if the driver supports safe console handling. This flag specifies that the server has to ensure exclusive access to console devices. Optionally the --force flag may be specified, requesting to disconnect any existing sessions, such as in a case of a broken connection.
cpu-stats
Syntax:
cpu-stats domain [--total] [start] [count]Provide cpu statistics information of a domain. The domain should be running. Default it shows stats for all CPUs, and a total. Use --total for only the total stats, start for only the per-cpu stats of the CPUs from start, count for only count CPUs' stats.
create
Syntax:
create FILE [--console] [--paused] [--autodestroy]
[--pass-fds N,M,...] [--validate] [--reset-nvram]Create a domain from an XML <file>. Optionally, --validate option can be passed to validate the format of the input XML file against an internal RNG schema (identical to using virt-xml-validate(1) tool). Domains created using this command are going to be either transient (temporary ones that will vanish once destroyed) or existing persistent guests that will run with one-time use configuration, leaving the persistent XML untouched (this can come handy during an automated testing of various configurations all based on the original XML). See the example below for usage demonstration.
The domain will be paused if the --paused option is used and supported by the driver; otherwise it will be running. If --console is requested, attach to the console after creation. If --autodestroy is requested, then the guest will be automatically destroyed when virsh closes its connection to libvirt, or otherwise exits.
If --pass-fds is specified, the argument is a comma separated list of open file descriptors which should be pass on into the guest. The file descriptors will be re-numbered in the guest, starting from 3. This is only supported with container based virtualization.
If --reset-nvram is specified, any existing NVRAM file will be deleted and re-initialized from its pristine template.
Example:
prepare a template from an existing domain (skip directly to 3a if writing one from scratch)
# virsh dumpxml <domain> > domain.xmledit the template using an editor of your choice and:
- DO CHANGE! <name> and <uuid> (<uuid> can also be removed), or
- DON'T CHANGE! either <name> or <uuid>
# $EDITOR domain.xmlcreate a domain from domain.xml, depending on whether following 2a or 2b respectively:
- the domain is going to be transient
- an existing persistent guest will run with a modified one-time configuration
# virsh create domain.xml
define
Syntax:
define FILE [--validate]Define a domain from an XML <file>. Optionally, the format of the input XML file can be validated against an internal RNG schema with --validate (identical to using virt-xml-validate(1) tool). The domain definition is registered but not started. If domain is already running, the changes will take effect on the next boot.
desc
Syntax:
desc domain [[--live] [--config] |
[--current]] [--title] [--edit] [--new-desc
New description or title message]Show or modify description and title of a domain. These values are user fields that allow storing arbitrary textual data to allow easy identification of domains. Title should be short, although it's not enforced. (See also metadata that works with XML based domain metadata.)
Flags --live or --config select whether this command works on live or persistent definitions of the domain. If both --live and --config are specified, the --config option takes precedence on getting the current description and both live configuration and config are updated while setting the description. --current is exclusive and implied if none of these was specified.
Flag --edit specifies that an editor with the contents of current description or title should be opened and the contents saved back afterwards.
Flag --title selects operation on the title field instead of description.
If neither of --edit and --new-desc are specified the note or description is displayed instead of being modified.
destroy
Syntax:
destroy domain [--graceful]Immediately terminate the domain domain. This doesn't give the domain OS any chance to react, and it's the equivalent of ripping the power cord out on a physical machine. In most cases you will want to use the shutdown command instead. However, this does not delete any storage volumes used by the guest, and if the domain is persistent, it can be restarted later.
If domain is transient, then the metadata of any snapshots will be lost once the guest stops running, but the snapshot contents still exist, and a new domain with the same name and UUID can restore the snapshot metadata with snapshot-create. Similarly, the metadata of any checkpoints will be lost, but can be restored with checkpoint-create.
If --graceful is specified, don't resort to extreme measures (e.g. SIGKILL) when the guest doesn't stop after a reasonable timeout; return an error instead.
domblkerror
Syntax:
domblkerror domainShow errors on block devices. This command usually comes handy when domstate command says that a domain was paused due to I/O error. The domblkerror command lists all block devices in error state and the error seen on each of them.
domblkinfo
Syntax:
domblkinfo domain [block-device --all] [--human]Get block device size info for a domain. A block-device corresponds to a unique target name (<target dev='name'/>) or source file (<source file='name'/>) for one of the disk devices attached to domain (see also domblklist for listing these names). If --human is set, the output will have a human readable output. If --all is set, the output will be a table showing all block devices size info associated with domain. The --all option takes precedence of the others.
domblklist
Syntax:
domblklist domain [--inactive] [--details]Print a table showing the brief information of all block devices associated with domain. If --inactive is specified, query the block devices that will be used on the next boot, rather than those currently in use by a running domain. If --details is specified, disk type and device value will also be printed. Other contexts that require a block device name (such as domblkinfo or snapshot-create for disk snapshots) will accept either target or unique source names printed by this command.
domblkstat
Syntax:
domblkstat domain [block-device] [--human]Get device block stats for a running domain. A block-device corresponds to a unique target name (<target dev='name'/>) or source file (<source file='name'/>) for one of the disk devices attached to domain (see also domblklist for listing these names). On a LXC or QEMU domain, omitting the block-device yields device block stats summarily for the entire domain.
Use --human for a more human readable output.
Availability of these fields depends on hypervisor. Unsupported fields are missing from the output. Other fields may appear if communicating with a newer version of libvirtd.
Explanation of fields (fields appear in the following order):
- rd_req - count of read operations
- rd_bytes - count of read bytes
- wr_req - count of write operations
- wr_bytes - count of written bytes
- errs - error count
- flush_operations - count of flush operations
- rd_total_times - total time read operations took (ns)
- wr_total_times - total time write operations took (ns)
- flush_total_times - total time flush operations took (ns)
- <-- other fields provided by hypervisor -->
domblkthreshold
Syntax:
domblkthreshold domain dev thresholdSet the threshold value for delivering the block-threshold event. dev specifies the disk device target or backing chain element of given device using the 'target[1]' syntax. threshold is a scaled value of the offset. If the block device should write beyond that offset the event will be delivered.
domcontrol
Syntax:
domcontrol domainReturns state of an interface to VMM used to control a domain. For states other than "ok" or "error" the command also prints number of seconds elapsed since the control interface entered its current state.
domdirtyrate-calc
Syntax:
domdirtyrate-calc <domain> [--seconds <sec>]Calculate an active domain's memory dirty rate which may be expected by user in order to decide whether it's proper to be migrated out or not. The seconds parameter can be used to calculate dirty rate in a specific time which allows 60s at most now and would be default to 1s if missing. The calculated dirty rate information is available by calling 'domstats --dirtyrate'.
domdisplay
Syntax:
domdisplay domain [--include-password] [[--type] type] [--all]Output a URI which can be used to connect to the graphical display of the domain via VNC, SPICE or RDP. The particular graphical display type can be selected using the type parameter (e.g. "vnc", "spice", "rdp"). If --include-password is specified, the SPICE channel password will be included in the URI. If --all is specified, then all show all possible graphical displays, for a VM could have more than one graphical displays.
domfsfreeze
Syntax:
domfsfreeze domain [[--mountpoint] mountpoint...]Freeze mounted filesystems within a running domain to prepare for consistent snapshots.
The --mountpoint option takes a parameter mountpoint, which is a mount point path of the filesystem to be frozen. This option can occur multiple times. If this is not specified, every mounted filesystem is frozen.
Note: snapshot-create command has a --quiesce option to freeze and thaw the filesystems automatically to keep snapshots consistent. domfsfreeze command is only needed when a user wants to utilize the native snapshot features of storage devices not supported by libvirt.
domfsinfo
Syntax:
domfsinfo domainShow a list of mounted filesystems within the running domain. The list contains mountpoints, names of a mounted device in the guest, filesystem types, and unique target names used in the domain XML (<target dev='name'/>).
Note that this command requires a guest agent configured and running in the domain's guest OS.
domfsthaw
Syntax:
domfsthaw domain [[--mountpoint] mountpoint...]Thaw mounted filesystems within a running domain, which have been frozen by domfsfreeze command.
The --mountpoint option takes a parameter mountpoint, which is a mount point path of the filesystem to be thawed. This option can occur multiple times. If this is not specified, every mounted filesystem is thawed.
domfstrim
Syntax:
domfstrim domain [--minimum bytes] [--mountpoint mountPoint]Issue a fstrim command on all mounted filesystems within a running domain. It discards blocks which are not in use by the filesystem. If --minimum bytes is specified, it tells guest kernel length of contiguous free range. Smaller than this may be ignored (this is a hint and the guest may not respect it). By increasing this value, the fstrim operation will complete more quickly for filesystems with badly fragmented free space, although not all blocks will be discarded. The default value is zero, meaning "discard every free block". Moreover, if a user wants to trim only one mount point, it can be specified via optional --mountpoint parameter.
domhostname
Syntax:
domhostname domain [--source lease|agent]Returns the hostname of a domain, if the hypervisor makes it available.
The --source argument specifies what data source to use for the hostnames, currently 'lease' to read DHCP leases or 'agent' to query the guest OS via an agent. If unspecified, driver returns the default method available (some drivers support only one type of source).
domid
Syntax:
domid domain-name-or-uuidConvert a domain name (or UUID) to a domain id
domif-getlink
Syntax:
domif-getlink domain interface-device [--config]Query link state of the domain's virtual interface. If --config is specified, query the persistent configuration, for compatibility purposes, --persistent is alias of --config.
interface-device can be the interface's target name or the MAC address.
domif-setlink
Syntax:
domif-setlink domain interface-device state [--config]Modify link state of the domain's virtual interface. Possible values for state are "up" and "down". If --config is specified, only the persistent configuration of the domain is modified, for compatibility purposes, --persistent is alias of --config. interface-device can be the interface's target name or the MAC address.
domifaddr
Syntax:
domifaddr domain [interface] [--full]
[--source lease|agent|arp]Get a list of interfaces of a running domain along with their IP and MAC addresses, or limited output just for one interface if interface is specified. Note that interface can be driver dependent, it can be the name within guest OS or the name you would see in domain XML. Moreover, the whole command may require a guest agent to be configured for the queried domain under some hypervisors, notably QEMU.
If --full is specified, the interface name and MAC address is always displayed when the interface has multiple IP addresses or aliases; otherwise, only the interface name and MAC address is displayed for the first name and MAC address with "-" for the others using the same name and MAC address.
The --source argument specifies what data source to use for the addresses, currently 'lease' to read DHCP leases, 'agent' to query the guest OS via an agent, or 'arp' to get IP from host's arp tables. If unspecified, 'lease' is the default.
backup-begin
Syntax:
backup-begin domain [backupxml] [checkpointxml] [--reuse-external]Begin a new backup job. If backupxml is omitted, this defaults to a full backup using a push model to filenames generated by libvirt; supplying XML allows fine-tuning such as requesting an incremental backup relative to an earlier checkpoint, controlling which disks participate or which filenames are involved, or requesting the use of a pull model backup. The backup-dumpxml command shows any resulting values assigned by libvirt. For more information on backup XML, see: https://libvirt.org/formatbackup.html
If --reuse-external is used it instructs libvirt to reuse temporary and output files provided by the user in backupxml.
If checkpointxml is specified, a second file with a top-level element of domaincheckpoint is used to create a simultaneous checkpoint, for doing a later incremental backup relative to the time the backup was created. See checkpoint-create for more details on checkpoints.
This command returns as soon as possible, and the backup job runs in the background; the progress of a push model backup can be checked with domjobinfo or by waiting for an event with event (the progress of a pull model backup is under the control of whatever third party connects to the NBD export). The job is ended with domjobabort.
backup-dumpxml
Syntax:
backup-dumpxml domainOutput XML describing the current backup job.
domiflist
Syntax:
domiflist domain [--inactive]Print a table showing the brief information of all virtual interfaces associated with domain. If --inactive is specified, query the virtual interfaces that will be used on the next boot, rather than those currently in use by a running domain. Other contexts that require a MAC address of virtual interface (such as detach-interface or domif-setlink) will accept the MAC address printed by this command.
domifstat
Syntax:
domifstat domain interface-deviceGet network interface stats for a running domain. The network interface stats are only available for interfaces that have a physical source interface. This does not include, for example, a 'user' interface type since it is a virtual LAN with NAT to the outside world. interface-device can be the interface target by name or MAC address.
domiftune
Syntax:
domiftune domain interface-device [[--config] [--live] | [--current]]
[*--inbound average,peak,burst,floor*]
[*--outbound average,peak,burst*]Set or query the domain's network interface's bandwidth parameters. interface-device can be the interface's target name (<target dev='name'/>), or the MAC address.
If no --inbound or --outbound is specified, this command will query and show the bandwidth settings. Otherwise, it will set the inbound or outbound bandwidth. average,peak,burst,floor is the same as in command attach-interface. Values for average, peak and floor are expressed in kilobytes per second, while burst is expressed in kilobytes in a single burst at peak speed as described in the Network XML documentation at https://libvirt.org/formatnetwork.html#elementQoS.
To clear inbound or outbound settings, use --inbound or --outbound respectfully with average value of zero.
If --live is specified, affect a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. If no flag is specified, behavior is different depending on hypervisor.
dominfo
Syntax:
dominfo domainReturns basic information about the domain.
domjobabort
Syntax:
domjobabort domainAbort the currently running domain job.
domjobinfo
Syntax:
domjobinfo domain [--completed [--keep-completed]] [--anystats] [--rawstats]Returns information about jobs running on a domain. --completed tells virsh to return information about a recently finished job. Statistics of a completed job are automatically destroyed once read (unless --keep-completed is used) or when libvirtd is restarted.
Normally only statistics for running and successful completed jobs are printed. --anystats can be used to also display statistics for failed jobs.
In case --rawstats is used, all fields are printed as received from the server without any attempts to interpret the data. The "Job type:" field is special, since it's reported by the API and not part of stats.
Note that time information returned for completed migrations may be completely irrelevant unless both source and destination hosts have synchronized time (i.e., NTP daemon is running on both of them).
domlaunchsecinfo
Syntax:
domlaunchsecinfo domainReturns information about the launch security parameters associated with a running domain.
The set of parameters reported will vary depending on which type of launch security protection is active. If none is active, no parameters will be reported.
domsetlaunchsecstate
Syntax:
domsetlaunchsecstate domain --secrethdr hdr-filename
--secret secret-filename [--set-address address]Set a launch security secret in the guest's memory. The guest must have a launchSecurity type enabled in its configuration and be in a paused state. On success, the guest can be transitioned to a running state. On failure, the guest should be destroyed.
--secrethdr specifies a filename containing the base64-encoded secret header. The header includes artifacts needed by the hypervisor firmware to recover the plain text of the launch secret. --secret specifies the filename containing the base64-encoded encrypted launch secret.
The --set-address option can be used to specify a physical address within the guest's memory to set the secret. If not specified, the address will be determined by the hypervisor.
dommemstat
Syntax:
dommemstat domain [--period seconds] [[--config] [--live] | [--current]]Get memory stats for a running domain.
Availability of these fields depends on hypervisor. Unsupported fields are missing from the output. Other fields may appear if communicating with a newer version of libvirtd.
Explanation of fields:
swap_in- The amount of data read from swap space (in KiB)swap_out- The amount of memory written out to swap space (in KiB)major_fault- The number of page faults where disk IO was requiredminor_fault- The number of other page faultsunused- The amount of memory left unused by the system (in KiB)available- The amount of usable memory as seen by the domain (in KiB)actual- Current balloon value (in KiB)rss- Resident Set Size of the running domain's process (in KiB)usable- The amount of memory which can be reclaimed by balloon without causing host swapping (in KiB)last-update- Timestamp of the last update of statistics (in seconds)disk_caches- The amount of memory that can be reclaimed without additional I/O, typically disk caches (in KiB)hugetlb_pgalloc- The number of successful huge page allocations initiated from within the domainhugetlb_pgfail- The number of failed huge page allocations initiated from within the domain
For QEMU/KVM with a memory balloon, setting the optional --period to a value larger than 0 in seconds will allow the balloon driver to return additional statistics which will be displayed by subsequent dommemstat commands. Setting the --period to 0 will stop the balloon driver collection, but does not clear the statistics in the balloon driver. Requires at least QEMU/KVM 1.5 to be running on the host.
The --live, --config, and --current flags are only valid when using the --period option in order to set the collection period for the balloon driver. If --live is specified, only the running guest collection period is affected. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest.
Both --live and --config flags may be given, but --current is exclusive. If no flag is specified, behavior is different depending on the guest state.
domname
Syntax:
domname domain-id-or-uuidConvert a domain Id (or UUID) to domain name
dompmsuspend
Syntax:
dompmsuspend domain target [--duration]Suspend a running domain into one of these states (possible target values):
mem- equivalent of S3 ACPI statedisk- equivalent of S4 ACPI statehybrid- RAM is saved to disk but not powered off
The --duration argument specifies number of seconds before the domain is woken up after it was suspended (see also dompmwakeup). Default is 0 for unlimited suspend time. (This feature isn't currently supported by any hypervisor driver and 0 should be used.).
Note that this command requires a guest agent configured and running in the domain's guest OS.
Beware that at least for QEMU, the domain's process will be terminated when target disk is used and a new process will be launched when libvirt is asked to wake up the domain. As a result of this, any runtime changes, such as device hotplug or memory settings, are lost unless such changes were made with --config flag.
dompmwakeup
Syntax:
dompmwakeup domainWakeup a domain from pmsuspended state (either suspended by dompmsuspend or from the guest itself). Injects a wakeup into the guest that is in pmsuspended state, rather than waiting for the previously requested duration (if any) to elapse. This operation does not necessarily fail if the domain is running.
domrename
Syntax:
domrename domain new-nameRename a domain. This command changes current domain name to the new name specified in the second argument.
Note: Domain must be inactive.
domstate
Syntax:
domstate domain [--reason]Returns state about a domain. --reason tells virsh to also print reason for the state.
domstats
Syntax:
domstats [--raw] [--enforce] [--backing] [--nowait] [--state]
[--cpu-total] [--balloon] [--vcpu] [--interface]
[--block] [--perf] [--iothread] [--memory] [--dirtyrate]
[[--list-active] [--list-inactive]
[--list-persistent] [--list-transient] [--list-running]y
[--list-paused] [--list-shutoff] [--list-other]] | [domain ...]Get statistics for multiple or all domains. Without any argument this command prints all available statistics for all domains.
The list of domains to gather stats for can be either limited by listing the domains as a space separated list, or by specifying one of the filtering flags --list-NNN. (The approaches can't be combined.)
By default some of the returned fields may be converted to more human friendly values by a set of pretty-printers. To suppress this behavior use the --raw flag.
The individual statistics groups are selectable via specific flags. By default all supported statistics groups are returned. Supported statistics groups flags are: --state, --cpu-total, --balloon, --vcpu, --interface, --block, --perf, --iothread, --memory, --dirtyrate.
Note that - depending on the hypervisor type and version or the domain state - not all of the following statistics may be returned.
When selecting the --state group the following fields are returned:
state.state- state of the VM, returned as number from virDomainState enumstate.reason- reason for entering given state, returned as int from virDomain*Reason enum corresponding to given state
--cpu-total returns:
cpu.time- total cpu time spent for this domain in nanosecondscpu.user- user cpu time spent in nanosecondscpu.system- system cpu time spent in nanosecondscpu.haltpoll.success.time- cpu halt polling success time spent in nanosecondscpu.haltpoll.fail.time- cpu halt polling fail time spent in nanosecondscpu.cache.monitor.count- the number of cache monitors for this domaincpu.cache.monitor.<num>.name- the name of cache monitor <num>cpu.cache.monitor.<num>.vcpus- vcpu list of cache monitor <num>cpu.cache.monitor.<num>.bank.count- the number of cache banks in cache monitor <num>cpu.cache.monitor.<num>.bank.<index>.id- host allocated cache id for bank <index> in cache monitor <num>cpu.cache.monitor.<num>.bank.<index>.bytes- the number of bytes of last level cache that the domain is using on cache bank <index>
--balloon returns:
balloon.current- the memory in KiB currently usedballoon.maximum- the maximum memory in KiB allowedballoon.swap_in- the amount of data read from swap space (in KiB)balloon.swap_out- the amount of memory written out to swap space (in KiB)balloon.major_fault- the number of page faults when disk IO was requiredballoon.minor_fault- the number of other page faultsballoon.unused- the amount of memory left unused by the system (in KiB)balloon.available- the amount of usable memory as seen by the domain (in KiB)balloon.rss- Resident Set Size of running domain's process (in KiB)balloon.usable- the amount of memory which can be reclaimed by balloon without causing host swapping (in KiB)balloon.last-update- timestamp of the last update of statistics (in seconds)balloon.disk_caches- the amount of memory that can be reclaimed without additional I/O, typically disk (in KiB)balloon.hugetlb_pgalloc- the number of successful huge page allocations from inside the domain via virtio balloonballoon.hugetlb_pgfail- the number of failed huge page allocations from inside the domain via virtio balloon
--vcpu returns:
vcpu.current- current number of online virtual CPUsvcpu.maximum- maximum number of online virtual CPUsvcpu.<num>.state- state of the virtual CPU <num>, as number from virVcpuState enumvcpu.<num>.time- virtual cpu time spent by virtual CPU <num> (in microseconds)vcpu.<num>.wait- virtual cpu time spent by virtual CPU <num> waiting on I/O (in microseconds)vcpu.<num>.halted- virtual CPU <num> is halted: yes or no (may indicate the processor is idle or even disabled, depending on the architecture)vcpu.<num>.delay- time the vCPU <num> thread was enqueued by the host scheduler, but was waiting in the queue instead of running. Exposed to the VM as a steal time.
--interface returns:
net.count- number of network interfaces on this domainnet.<num>.name- name of the interface <num>net.<num>.rx.bytes- number of bytes receivednet.<num>.rx.pkts- number of packets receivednet.<num>.rx.errs- number of receive errorsnet.<num>.rx.drop- number of receive packets droppednet.<num>.tx.bytes- number of bytes transmittednet.<num>.tx.pkts- number of packets transmittednet.<num>.tx.errs- number of transmission errorsnet.<num>.tx.drop- number of transmit packets dropped
--perf returns the statistics of all enabled perf events:
perf.cmt- the cache usage in Byte currently usedperf.mbmt- total system bandwidth from one level of cacheperf.mbml- bandwidth of memory traffic for a memory controllerperf.cpu_cycles- the count of cpu cycles (total/elapsed)perf.instructions- the count of instructionsperf.cache_references- the count of cache hitsperf.cache_misses- the count of caches missesperf.branch_instructions- the count of branch instructionsperf.branch_misses- the count of branch missesperf.bus_cycles- the count of bus cyclesperf.stalled_cycles_frontend- the count of stalled frontend cpu cyclesperf.stalled_cycles_backend- the count of stalled backend cpu cyclesperf.ref_cpu_cycles- the count of ref cpu cyclesperf.cpu_clock- the count of cpu clock timeperf.task_clock- the count of task clock timeperf.page_faults- the count of page faultsperf.context_switches- the count of context switchesperf.cpu_migrations- the count of cpu migrationsperf.page_faults_min- the count of minor page faultsperf.page_faults_maj- the count of major page faultsperf.alignment_faults- the count of alignment faultsperf.emulation_faults- the count of emulation faults
See the perf command for more details about each event.
--block returns information about disks associated with each domain. Using the --backing flag extends this information to cover all resources in the backing chain, rather than the default of limiting information to the active layer for each guest disk. Information listed includes:
block.count- number of block devices being listedblock.<num>.name- name of the target of the block device <num> (the same name for multiple entries if --backing is present)block.<num>.backingIndex- when --backing is present, matches up with the <backingStore> index listed in domain XML for backing filesblock.<num>.path- file source of block device <num>, if it is a local file or block deviceblock.<num>.rd.reqs- number of read requestsblock.<num>.rd.bytes- number of read bytesblock.<num>.rd.times- total time (ns) spent on readsblock.<num>.wr.reqs- number of write requestsblock.<num>.wr.bytes- number of written bytesblock.<num>.wr.times- total time (ns) spent on writesblock.<num>.fl.reqs- total flush requestsblock.<num>.fl.times- total time (ns) spent on cache flushingblock.<num>.errors- Xen only: the 'oo_req' valueblock.<num>.allocation- offset of highest written sector in bytesblock.<num>.capacity- logical size of source file in bytesblock.<num>.physical- physical size of source file in bytesblock.<num>.threshold- threshold (in bytes) for delivering the VIR_DOMAIN_EVENT_ID_BLOCK_THRESHOLD event. See domblkthreshold.
--iothread returns information about IOThreads on the running guest if supported by the hypervisor.
The "poll-max-ns" for each thread is the maximum nanoseconds to allow each polling interval to occur. A polling interval is a period of time allowed for a thread to process data before being the guest gives up its CPU quantum back to the host. A value set too small will not allow the IOThread to run long enough on a CPU to process data. A value set too high will consume too much CPU time per IOThread failing to allow other threads running on the CPU to get time. The polling interval is not available for statistical purposes.
iothread.count- maximum number of IOThreads in the subsequent listas unsigned int. Each IOThread in the list will will use it's iothread_id value as the <id>. There may be fewer <id> entries than the iothread.count value if the polling values are not supported.
iothread.<id>.poll-max-ns- maximum polling time in nanoseconds used by the <id> IOThread. A value of 0 (zero) indicates polling is disabled.iothread.<id>.poll-grow- polling time grow value. A value of 0 (zero) growth is managed by the hypervisor.iothread.<id>.poll-shrink- polling time shrink value. A value of (zero) indicates shrink is managed by hypervisor.
--memory returns:
memory.bandwidth.monitor.count- the number of memory bandwidth monitors for this domainmemory.bandwidth.monitor.<num>.name- the name of monitor <num>memory.bandwidth.monitor.<num>.vcpus- the vcpu list of monitor <num>memory.bandwidth.monitor.<num>.node.count- the number of memorycontroller in monitor <num>
memory.bandwidth.monitor.<num>.node.<index>.id- host allocated memory controller id for controller <index> of monitor <num>memory.bandwidth.monitor.<num>.node.<index>.bytes.local- the accumulative bytes consumed by @vcpus that passing through the memory controller in the same processor that the scheduled host CPU belongs to.memory.bandwidth.monitor.<num>.node.<index>.bytes.total- the total bytes consumed by @vcpus that passing through all memory controllers, either local or remote controller.
--dirtyrate returns:
dirtyrate.calc_status- the status of last memory dirty rate calculation, returned as number from virDomainDirtyRateStatus enum.dirtyrate.calc_start_time- the start time of last memory dirty rate calculation.dirtyrate.calc_period- the period of last memory dirty rate calculation.dirtyrate.megabytes_per_second- the calculated memory dirty rate in MiB/s.
Selecting a specific statistics groups doesn't guarantee that the daemon supports the selected group of stats. Flag --enforce forces the command to fail if the daemon doesn't support the selected group.
When collecting stats libvirtd may wait for some time if there's already another job running on given domain for it to finish. This may cause unnecessary delay in delivering stats. Using --nowait suppresses this behaviour. On the other hand some statistics might be missing for such domain.
domtime
Syntax:
domtime domain { [--now] [--pretty] [--sync] [--time time] }Gets or sets the domain's system time. When run without any arguments (but domain), the current domain's system time is printed out. The --pretty modifier can be used to print the time in more human readable form.
When --time time is specified, the domain's time is not gotten but set instead. The --now modifier acts like if it was an alias for --time $now, which means it sets the time that is currently on the host virsh is running at. In both cases (setting and getting), time is in seconds relative to Epoch of 1970-01-01 in UTC. The --sync modifies the set behavior a bit: The time passed is ignored, but the time to set is read from domain's RTC instead. Please note, that some hypervisors may require a guest agent to be configured in order to get or set the guest time.
domuuid
Syntax:
domuuid domain-name-or-idConvert a domain name or id to domain UUID
domxml-from-native
Syntax:
domxml-from-native format configConvert the file config in the native guest configuration format named by format to a domain XML format. For QEMU/KVM hypervisor, the format argument must be qemu-argv. For Xen hypervisor, the format argument may be xen-xm, xen-xl, or xen-sxpr. For LXC hypervisor, the format argument must be lxc-tools. For VMware/ESX hypervisor, the format argument must be vmware-vmx. For the Bhyve hypervisor, the format argument must be bhyve-argv.
domxml-to-native
Syntax:
domxml-to-native format { [--xml] xml | --domain domain-name-or-id-or-uuid }Convert the file xml into domain XML format or convert an existing --domain to the native guest configuration format named by format. The xml and --domain arguments are mutually exclusive. For the types of format argument, refer to domxml-from-native.
dump
Syntax:
dump domain corefilepath [--bypass-cache]
{ [--live] | [--crash] | [--reset] }
[--verbose] [--memory-only] [--format string]Dumps the core of a domain to a file for analysis. If --live is specified, the domain continues to run until the core dump is complete, rather than pausing up front. If --crash is specified, the domain is halted with a crashed status, rather than merely left in a paused state. If --reset is specified, the domain is reset after successful dump. Note, these three switches are mutually exclusive. If --bypass-cache is specified, the save will avoid the file system cache, although this may slow down the operation. If --memory-only is specified, the file is elf file, and will only include domain's memory and cpu common register value. It is very useful if the domain uses host devices directly. --format string is used to specify the format of 'memory-only' dump, and string can be one of: elf, kdump-zlib(kdump-compressed format with zlib-compressed), kdump-lzo(kdump-compressed format with lzo-compressed), kdump-snappy(kdump-compressed format with snappy-compressed), win-dmp(Windows full crashdump format).
The progress may be monitored using domjobinfo virsh command and canceled with domjobabort command (sent by another virsh instance). Another option is to send SIGINT (usually with Ctrl-C) to the virsh process running dump command. --verbose displays the progress of dump.
NOTE: Some hypervisors may require the user to manually ensure proper permissions on file and path specified by argument corefilepath.
NOTE: Crash dump in a old kvmdump format is being obsolete and cannot be loaded and processed by crash utility since its version 6.1.0. A --memory-only option is required in order to produce valid ELF file which can be later processed by the crash utility.
dumpxml
Syntax:
dumpxml domain [--inactive] [--security-info] [--update-cpu] [--migratable]Output the domain information as an XML dump to stdout, this format can be used by the create command. Additional options affecting the XML dump may be used. --inactive tells virsh to dump domain configuration that will be used on next start of the domain as opposed to the current domain configuration. Using --security-info will also include security sensitive information in the XML dump. --update-cpu updates domain CPU requirements according to host CPU. With --migratable one can request an XML that is suitable for migrations, i.e., compatible with older libvirt releases and possibly amended with internal run-time options. This option may automatically enable other options (--update-cpu, --security-info, ...) as necessary.
edit
Syntax:
edit domainEdit the XML configuration file for a domain, which will affect the next boot of the guest.
This is equivalent to:
virsh dumpxml --inactive --security-info domain > domain.xml
vi domain.xml (or make changes with your other text editor)
virsh define domain.xmlexcept that it does some error checking.
The editor used can be supplied by the $VISUAL or $EDITOR environment variables, and defaults to vi.
emulatorpin
Syntax:
emulatorpin domain [cpulist] [[--live] [--config] | [--current]]Query or change the pinning of domain's emulator threads to host physical CPUs.
See vcpupin for cpulist.
If --live is specified, affect a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given if cpulist is present, but --current is exclusive. If no flag is specified, behavior is different depending on hypervisor.
event
Syntax:
event {[domain] { event | --all } [--loop] [--timeout seconds] [--timestamp] | --list}Wait for a class of domain events to occur, and print appropriate details of events as they happen. The events can optionally be filtered by domain. Using --list as the only argument will provide a list of possible event values known by this client, although the connection might not allow registering for all these events. It is also possible to use --all instead of event to register for all possible event types at once.
By default, this command is one-shot, and returns success once an event occurs; you can send SIGINT (usually via Ctrl-C) to quit immediately. If --timeout is specified, the command gives up waiting for events after seconds have elapsed. With --loop, the command prints all events until a timeout or interrupt key.
When --timestamp is used, a human-readable timestamp will be printed before the event.
get-user-sshkeys
Syntax:
get-user-sshkeys domain userPrint SSH authorized keys for given user in the guest domain. Please note, that an entry in the file has internal structure as defined by sshd(8) and virsh/libvirt does handle keys as opaque strings, i.e. does not interpret them.
guest-agent-timeout
Syntax:
guest-agent-timeout domain [--timeout value]Set how long to wait for a response from guest agent commands. By default, agent commands block forever waiting for a response. value must be a positive value (wait for given amount of seconds) or one of the following values:
- -2 - block forever waiting for a result (used when --timeout is omitted),
- -1 - reset timeout to the default value (currently defined as 5 seconds in libvirt daemon),
- 0 - do not wait at all,
guestinfo
Syntax:
guestinfo domain [--user] [--os] [--timezone] [--hostname] [--filesystem]
[--disk] [--interface]Print information about the guest from the point of view of the guest agent. Note that this command requires a guest agent to be configured and running in the domain's guest OS.
When run without any arguments, this command prints all information types that are supported by the guest agent at that point, omitting unavailable ones. Success is always reported in this case.
You can limit the types of information that are returned by specifying one or more flags. Available information types flags are --user, --os, --timezone, --hostname, --filesystem, --disk and --interface. If an explicitly requested information type is not supported by the guest agent at that point, the processes will provide an exit code of 1.
Note that depending on the hypervisor type and the version of the guest agent running within the domain, not all of the following information may be returned.
When selecting the --user information type, the following fields may be returned:
user.count- the number of active users on this domainuser.<num>.name- username of user <num>user.<num>.domain- domain of the user <num> (may only be present on certain guets types)user.<num>.login-time- the login time of user <num> in milliseconds since the epoch
--os returns:
os.id- a string identifying the operating systemos.name- the name of the operating systemos.pretty-name- a pretty name for the operating systemos.version- the version of the operating systemos.version-id- the version id of the operating systemos.kernel-release- the release of the operating system kernelos.kernel-version- the version of the operating system kernelos.machine- the machine hardware nameos.variant- a specific variant or edition of the operating systemos.variant-id- the id for a specific variant or edition of the operating system
--timezone returns:
timezone.name- the name of the timezonetimezone.offset- the offset to UTC in seconds
--hostname returns:
hostname- the hostname of the domain
--filesystem returns:
fs.count- the number of filesystems defined on this domainfs.<num>.mountpoint- the path to the mount point for filesystem <num>fs.<num>.name- device name in the guest (e.g.sda1) for filesystem <num>fs.<num>.fstype- the type of filesystem <num>fs.<num>.total-bytes- the total size of filesystem <num>fs.<num>.used-bytes- the number of bytes used in filesystem <num>fs.<num>.disk.count- the number of disks targeted by filesystem <num>fs.<num>.disk.<num>.alias- the device alias of disk <num> (e.g. sda)fs.<num>.disk.<num>.serial- the serial number of disk <num>fs.<num>.disk.<num>.device- the device node of disk <num>
--disk returns:
disk.count- the number of disks defined on this domaindisk.<num>.name- device node (Linux) or device UNC (Windows)disk.<num>.partition- whether this is a partition or diskdisk.<num>.dependency.count- the number of device dependenciesdisk.<num>.dependency.<num>.name- a dependency namedisk.<num>.serial- optional disk serial numberdisk.<num>.alias- the device alias of the disk (e.g. sda)disk.<num>.guest_alias- optional alias assigned to the disk
--interface returns: * if.count - the number of interfaces defined on this domain * if.<num>.name - name in the guest (e.g. eth0) for interface <num> * if.<num>.hwaddr - hardware address in the guest for interface <num> * if.<num>.addr.count - the number of IP addresses of interface <num> * if.<num>.addr.<num1>.type - the IP address type of addr <num1> (e.g. ipv4) * if.<num>.addr.<num1>.addr - the IP address of addr <num1> * if.<num>.addr.<num1>.prefix - the prefix of IP address of addr <num1>
guestvcpus
Syntax:
guestvcpus domain [[--enable] | [--disable]] [cpulist]Query or change state of vCPUs from guest's point of view using the guest agent. When invoked without cpulist the guest is queried for available guest vCPUs, their state and possibility to be offlined.
If cpulist is provided then one of --enable or --disable must be provided too. The desired operation is then executed on the domain.
See vcpupin for information on cpulist.
iothreadadd
Syntax:
iothreadadd domain iothread_id [[--config] [--live] | [--current]]Add a new IOThread to the domain using the specified iothread_id. If the iothread_id already exists, the command will fail. The iothread_id must be greater than zero.
If --live is specified, affect a running guest. If the guest is not running an error is returned. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest.
iothreaddel
Syntax:
iothreaddel domain iothread_id [[--config] [--live] | [--current]]Delete an IOThread from the domain using the specified iothread_id. If an IOThread is currently assigned to a disk resource such as via the attach-disk command, then the attempt to remove the IOThread will fail. If the iothread_id does not exist an error will occur.
If --live is specified, affect a running guest. If the guest is not running an error is returned. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest.
iothreadinfo
Syntax:
iothreadinfo domain [[--live] [--config] | [--current]]Display basic domain IOThreads information including the IOThread ID and the CPU Affinity for each IOThread.
If --live is specified, get the IOThreads data from the running guest. If the guest is not running, an error is returned. If --config is specified, get the IOThreads data from the next start of a persistent guest. If --current is specified or --live and --config are not specified, then get the IOThread data based on the current guest state, which can either be live or offline.
iothreadpin
Syntax:
iothreadpin domain iothread cpulist [[--live] [--config] | [--current]]Change the pinning of a domain IOThread to host physical CPUs. In order to retrieve a list of all IOThreads, use iothreadinfo. To pin an iothread specify the cpulist desired for the IOThread ID as listed in the iothreadinfo output.
cpulist is a list of physical CPU numbers. Its syntax is a comma separated list and a special markup using '-' and '^' (ex. '0-4', '0-3,^2') can also be allowed. The '-' denotes the range and the '^' denotes exclusive. If you want to reset iothreadpin setting, that is, to pin an iothread to all physical cpus, simply specify 'r' as a cpulist.
If --live is specified, affect a running guest. If the guest is not running, an error is returned. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given if cpulist is present, but --current is exclusive. If no flag is specified, behavior is different depending on hypervisor.
Note: The expression is sequentially evaluated, so "0-15,^8" is identical to "9-14,0-7,15" but not identical to "^8,0-15".
iothreadset
Syntax:
iothreadset domain iothread_id [[--poll-max-ns ns] [--poll-grow factor]
[--poll-shrink divisor]]
[[--config] [--live] | [--current]]Modifies an existing iothread of the domain using the specified iothread_id. The --poll-max-ns provides the maximum polling interval to be allowed for an IOThread in ns. If a 0 (zero) is provided, then polling for the IOThread is disabled. The --poll-grow is the factor by which the current polling time will be adjusted in order to reach the maximum polling time. If a 0 (zero) is provided, then the default factor will be used. The --poll-shrink is the quotient by which the current polling time will be reduced in order to get below the maximum polling interval. If a 0 (zero) is provided, then the default quotient will be used. The polling values are purely dynamic for a running guest. Saving, destroying, stopping, etc. the guest will result in the polling values returning to hypervisor defaults at the next start, restore, etc.
If --live is specified, affect a running guest. If the guest is not running an error is returned. If --current is specified or --live is not specified, then handle as if --live was specified. (Where "current" here means whatever the present guest state is: live or offline.)
managedsave
Syntax:
managedsave domain [--bypass-cache] [{--running | --paused}] [--verbose]Save and destroy (stop) a running domain, so it can be restarted from the same state at a later time. When the virsh start command is next run for the domain, it will automatically be started from this saved state. If --bypass-cache is specified, the save will avoid the file system cache, although this may slow down the operation.
The progress may be monitored using domjobinfo virsh command and canceled with domjobabort command (sent by another virsh instance). Another option is to send SIGINT (usually with Ctrl-C) to the virsh process running managedsave command. --verbose displays the progress of save.
Normally, starting a managed save will decide between running or paused based on the state the domain was in when the save was done; passing either the --running or --paused flag will allow overriding which state the start should use.
The dominfo command can be used to query whether a domain currently has any managed save image.
managedsave-define
Syntax:
managedsave-define domain xml [{--running | --paused}]Update the domain XML that will be used when domain is later started. The xml argument must be a file name containing the alternative XML, with changes only in the host-specific portions of the domain XML. For example, it can be used to change disk file paths.
The managed save image records whether the domain should be started to a running or paused state. Normally, this command does not alter the recorded state; passing either the --running or --paused flag will allow overriding which state the start should use.
managedsave-dumpxml
Syntax:
managedsave-dumpxml domain [--security-info]Extract the domain XML that was in effect at the time the saved state file file was created with the managedsave command. Using --security-info will also include security sensitive information.
managedsave-edit
Syntax:
managedsave-edit domain [{--running | --paused}]Edit the XML configuration associated with a saved state file of a domain was created by the managedsave command.
The managed save image records whether the domain should be started to a running or paused state. Normally, this command does not alter the recorded state; passing either the --running or --paused flag will allow overriding which state the restore should use.
This is equivalent to:
virsh managedsave-dumpxml domain-name > state-file.xml
vi state-file.xml (or make changes with your other text editor)
virsh managedsave-define domain-name state-file-xmlexcept that it does some error checking.
The editor used can be supplied by the $VISUAL or $EDITOR environment variables, and defaults to vi.
managedsave-remove
Syntax:
managedsave-remove domainRemove the managedsave state file for a domain, if it exists. This ensures the domain will do a full boot the next time it is started.
maxvcpus
Syntax:
maxvcpus [type]Provide the maximum number of virtual CPUs supported for a guest VM on this connection. If provided, the type parameter must be a valid type attribute for the <domain> element of XML.
memtune
Syntax:
memtune domain [--hard-limit size] [--soft-limit size] [--swap-hard-limit size]
[--min-guarantee size] [[--config] [--live] | [--current]]Allows you to display or set the domain memory parameters. Without flags, the current settings are displayed; with a flag, the appropriate limit is adjusted if supported by the hypervisor. LXC and QEMU/KVM support --hard-limit, --soft-limit, and --swap-hard-limit. --min-guarantee is supported only by ESX hypervisor. Each of these limits are scaled integers (see NOTES above), with a default of kibibytes (blocks of 1024 bytes) if no suffix is present. Libvirt rounds up to the nearest kibibyte. Some hypervisors require a larger granularity than KiB, and requests that are not an even multiple will be rounded up. For example, vSphere/ESX rounds the parameter up to mebibytes (1024 kibibytes).
If --live is specified, affect a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. If no flag is specified, behavior is different depending on hypervisor.
For QEMU/KVM, the parameters are applied to the QEMU process as a whole. Thus, when counting them, one needs to add up guest RAM, guest video RAM, and some memory overhead of QEMU itself. The last piece is hard to determine so one needs guess and try.
For LXC, the displayed hard_limit value is the current memory setting from the XML or the results from a virsh setmem command.
--hard-limit
The maximum memory the guest can use.
--soft-limit
The memory limit to enforce during memory contention.
--swap-hard-limit
The maximum memory plus swap the guest can use. This has to be more than hard-limit value provided.
--min-guarantee
The guaranteed minimum memory allocation for the guest.
Specifying -1 as a value for these limits is interpreted as unlimited.
metadata
Syntax:
metadata domain [[--live] [--config] | [--current]]
[--edit] [uri] [key] [set] [--remove]Show or modify custom XML metadata of a domain. The metadata is a user defined XML that allows storing arbitrary XML data in the domain definition. Multiple separate custom metadata pieces can be stored in the domain XML. The pieces are identified by a private XML namespace provided via the uri argument. (See also desc that works with textual metadata of a domain.)
Flags --live or --config select whether this command works on live or persistent definitions of the domain. If both --live and --config are specified, the --config option takes precedence on getting the current description and both live configuration and config are updated while setting the description. --current is exclusive and implied if none of these was specified.
Flag --remove specifies that the metadata element specified by the uri argument should be removed rather than updated.
Flag --edit specifies that an editor with the metadata identified by the uri argument should be opened and the contents saved back afterwards. Otherwise the new contents can be provided via the set argument.
When setting metadata via --edit or set the key argument must be specified and is used to prefix the custom elements to bind them to the private namespace.
If neither of --edit and set are specified the XML metadata corresponding to the uri namespace is displayed instead of being modified.
migrate
Syntax:
migrate [--live] [--offline] [--direct] [--p2p [--tunnelled]]
[--persistent] [--undefinesource] [--suspend] [--copy-storage-all]
[--copy-storage-inc] [--change-protection] [--unsafe] [--verbose]
[--rdma-pin-all] [--abort-on-error] [--postcopy] [--postcopy-after-precopy]
domain desturi [migrateuri] [graphicsuri] [listen-address] [dname]
[--timeout seconds [--timeout-suspend | --timeout-postcopy]]
[--xml file] [--migrate-disks disk-list] [--disks-port port]
[--compressed] [--comp-methods method-list]
[--comp-mt-level] [--comp-mt-threads] [--comp-mt-dthreads]
[--comp-xbzrle-cache] [--auto-converge] [auto-converge-initial]
[auto-converge-increment] [--persistent-xml file] [--tls]
[--postcopy-bandwidth bandwidth]
[--parallel [--parallel-connections connections]]
[--bandwidth bandwidth] [--tls-destination hostname]
[--disks-uri URI] [--copy-storage-synchronous-writes]Migrate domain to another host. Add --live for live migration; <--p2p> for peer-2-peer migration; --direct for direct migration; or --tunnelled for tunnelled migration. --offline migrates domain definition without starting the domain on destination and without stopping it on source host. Offline migration may be used with inactive domains and it must be used with --persistent option.
--persistent leaves the domain persistent on destination host, --undefinesource undefines the domain on the source host, and --suspend leaves the domain paused on the destination host.
--copy-storage-all indicates migration with non-shared storage with full disk copy, --copy-storage-inc indicates migration with non-shared storage with incremental copy (same base image shared between source and destination). In both cases the disk images have to exist on destination host, the --copy-storage-... options only tell libvirt to transfer data from the images on source host to the images found at the same place on the destination host. By default only non-shared non-readonly images are transferred. Use --migrate-disks to explicitly specify a list of disk targets to transfer via the comma separated disk-list argument. With --copy-storage-synchronous-writes flag used the disk data migration will synchronously handle guest disk writes to both the original source and the destination to ensure that the disk migration converges at the price of possibly decreased burst performance.
--change-protection enforces that no incompatible configuration changes will be made to the domain while the migration is underway; this flag is implicitly enabled when supported by the hypervisor, but can be explicitly used to reject the migration if the hypervisor lacks change protection support.
--verbose displays the progress of migration.
--abort-on-error cancels the migration if a soft error (for example I/O error) happens during the migration.
--postcopy enables post-copy logic in migration, but does not actually start post-copy, i.e., migration is started in pre-copy mode. Once migration is running, the user may switch to post-copy using the migrate-postcopy command sent from another virsh instance or use --postcopy-after-precopy along with --postcopy to let libvirt automatically switch to post-copy after the first pass of pre-copy is finished. The maximum bandwidth consumed during the post-copy phase may be limited using --postcopy-bandwidth. The maximum bandwidth consumed during the pre-copy phase may be limited using --bandwidth.
--auto-converge forces convergence during live migration. The initial guest CPU throttling rate can be set with auto-converge-initial. If the initial throttling rate is not enough to ensure convergence, the rate is periodically increased by auto-converge-increment.
--rdma-pin-all can be used with RDMA migration (i.e., when migrateuri starts with rdma://) to tell the hypervisor to pin all domain's memory at once before migration starts rather than letting it pin memory pages as needed. For QEMU/KVM this requires hard_limit memory tuning element (in the domain XML) to be used and set to the maximum memory configured for the domain plus any memory consumed by the QEMU process itself. Beware of setting the memory limit too high (and thus allowing the domain to lock most of the host's memory). Doing so may be dangerous to both the domain and the host itself since the host's kernel may run out of memory.
Note: Individual hypervisors usually do not support all possible types of migration. For example, QEMU does not support direct migration.
In some cases libvirt may refuse to migrate the domain because doing so may lead to potential problems such as data corruption, and thus the migration is considered unsafe. For QEMU domain, this may happen if the domain uses disks without explicitly setting cache mode to "none". Migrating such domains is unsafe unless the disk images are stored on coherent clustered filesystem, such as GFS2 or GPFS. If you are sure the migration is safe or you just do not care, use --unsafe to force the migration.
dname is used for renaming the domain to new name during migration, which also usually can be omitted. Likewise, --xml file is usually omitted, but can be used to supply an alternative XML file for use on the destination to supply a larger set of changes to any host-specific portions of the domain XML, such as accounting for naming differences between source and destination in accessing underlying storage. If --persistent is enabled, --persistent-xml file can be used to supply an alternative XML file which will be used as the persistent guest definition on the destination host.
--timeout seconds tells virsh to run a specified action when live migration exceeds that many seconds. It can only be used with --live. If --timeout-suspend is specified, the domain will be suspended after the timeout and the migration will complete offline; this is the default if no --timeout-\`` option is specified on the command line. When--timeout-postcopy* is used, virsh will switch migration from pre-copy to post-copy upon timeout; migration has to be started with --postcopy option for this to work.
--compressed activates compression, the compression method is chosen with --comp-methods. Supported methods are "mt" and "xbzrle" and can be used in any combination. When no methods are specified, a hypervisor default methods will be used. QEMU defaults to "xbzrle". Compression methods can be tuned further. --comp-mt-level sets compression level. Values are in range from 0 to 9, where 1 is maximum speed and 9 is maximum compression. --comp-mt-threads and --comp-mt-dthreads set the number of compress threads on source and the number of decompress threads on target respectively. --comp-xbzrle-cache sets size of page cache in bytes.
Providing --tls causes the migration to use the host configured TLS setup (see migrate_tls_x509_cert_dir in /etc/libvirt/qemu.conf) in order to perform the migration of the domain. Usage requires proper TLS setup for both source and target. Normally the TLS certificate from the destination host must match the host's name for TLS verification to succeed. When the certificate does not match the destination hostname and the expected certificate's hostname is known, --tls-destination can be used to pass the expected hostname when starting the migration.
--parallel option will cause migration data to be sent over multiple parallel connections. The number of such connections can be set using --parallel-connections. Parallel connections may help with saturating the network link between the source and the target and thus speeding up the migration.
Running migration can be canceled by interrupting virsh (usually using Ctrl-C) or by domjobabort command sent from another virsh instance.
The desturi and migrateuri parameters can be used to control which destination the migration uses. desturi is important for managed migration, but unused for direct migration; migrateuri is required for direct migration, but can usually be automatically determined for managed migration.
Note: The desturi parameter for normal migration and peer2peer migration has different semantics:
- normal migration: the desturi is an address of the target host as seen from the client machine.
- peer2peer migration: the desturi is an address of the target host as seen from the source machine.
In a special circumstance where you require a complete control of the connection and/or libvirt does not have network access to the remote side you can use a UNIX transport in the URI and specify a socket path in the query, for example with the qemu driver you could use this:
qemu+unix:///system?socket=/path/to/socketWhen migrateuri is not specified, libvirt will automatically determine the hypervisor specific URI. Some hypervisors, including QEMU, have an optional "migration_host" configuration parameter (useful when the host has multiple network interfaces). If this is unspecified, libvirt determines a name by looking up the target host's configured hostname.
There are a few scenarios where specifying migrateuri may help:
- The configured hostname is incorrect, or DNS is broken. If a host has a hostname which will not resolve to match one of its public IP addresses, then libvirt will generate an incorrect URI. In this case migrateuri should be explicitly specified, using an IP address, or a correct hostname.
- The host has multiple network interfaces. If a host has multiple network interfaces, it might be desirable for the migration data stream to be sent over a specific interface for either security or performance reasons. In this case migrateuri should be explicitly specified, using an IP address associated with the network to be used.
- The firewall restricts what ports are available. When libvirt generates a migration URI, it will pick a port number using hypervisor specific rules. Some hypervisors only require a single port to be open in the firewalls, while others require a whole range of port numbers. In the latter case migrateuri might be specified to choose a specific port number outside the default range in order to comply with local firewall policies.
- The desturi uses UNIX transport method. In this advanced case libvirt should not guess a migrateuri and it should be specified using UNIX socket path URI:
unix:///path/to/socketSee https://libvirt.org/migration.html#uris for more details on migration URIs.
Optional graphicsuri overrides connection parameters used for automatically reconnecting a graphical clients at the end of migration. If omitted, libvirt will compute the parameters based on target host IP address. In case the client does not have a direct access to the network virtualization hosts are connected to and needs to connect through a proxy, graphicsuri may be used to specify the address the client should connect to. The URI is formed as follows:
protocol://hostname[:port]/[?parameters]where protocol is either "spice" or "vnc" and parameters is a list of protocol specific parameters separated by '&'. Currently recognized parameters are "tlsPort" and "tlsSubject". For example,
spice://target.host.com:1234/?tlsPort=4567Optional listen-address sets the listen address that hypervisor on the destination side should bind to for incoming migration. Both IPv4 and IPv6 addresses are accepted as well as hostnames (the resolving is done on destination). Some hypervisors do not support specifying the listen address and will return an error if this parameter is used. This parameter cannot be used if desturi uses UNIX transport method.
Optional disks-port sets the port that hypervisor on destination side should bind to for incoming disks traffic. Currently it is supported only by QEMU.
Optional disks-uri can also be specified (mutually exclusive with disks-port) to specify what the remote hypervisor should bind/connect to when migrating disks. This can be tcp://address:port to specify a listen address (which overrides --migrate-uri and --listen-address for the disk migration) and a port or unix:///path/to/socket in case you need the disk migration to happen over a UNIX socket with that specified path. In this case you need to make sure the same socket path is accessible to both source and destination hypervisors and connecting to the socket on the source (after hypervisor creates it on the destination) will actually connect to the destination. If you are using SELinux (at least on the source host) you need to make sure the socket on the source is accessible to libvirtd/QEMU for connection. Libvirt cannot change the context of the existing socket because it is different from the file representation of the socket and the context is chosen by its creator (usually by using setsockcreatecon{,_raw}() functions).
migrate-compcache
Syntax:
migrate-compcache domain [--size bytes]Sets and/or gets size of the cache (in bytes) used for compressing repeatedly transferred memory pages during live migration. When called without size, the command just prints current size of the compression cache. When size is specified, the hypervisor is asked to change compression cache to size bytes and then the current size is printed (the result may differ from the requested size due to rounding done by the hypervisor). The size option is supposed to be used while the domain is being live-migrated as a reaction to migration progress and increasing number of compression cache misses obtained from domjobinfo.
migrate-getmaxdowntime
Syntax:
migrate-getmaxdowntime domainGet the maximum tolerable downtime for a domain which is being live-migrated to another host. This is the number of milliseconds the guest is allowed to be down at the end of live migration.
migrate-getspeed
Syntax:
migrate-getspeed domain [--postcopy]Get the maximum migration bandwidth (in MiB/s) for a domain. If the --postcopy option is specified, the command will get the maximum bandwidth allowed during a post-copy migration phase.
migrate-postcopy
Syntax:
migrate-postcopy domainSwitch the current migration from pre-copy to post-copy. This is only supported for a migration started with --postcopy option.
migrate-setmaxdowntime
Syntax:
migrate-setmaxdowntime domain downtimeSet maximum tolerable downtime for a domain which is being live-migrated to another host. The downtime is a number of milliseconds the guest is allowed to be down at the end of live migration.
migrate-setspeed
Syntax:
migrate-setspeed domain bandwidth [--postcopy]Set the maximum migration bandwidth (in MiB/s) for a domain which is being migrated to another host. bandwidth is interpreted as an unsigned long long value. Specifying a negative value results in an essentially unlimited value being provided to the hypervisor. The hypervisor can choose whether to reject the value or convert it to the maximum value allowed. If the --postcopy option is specified, the command will set the maximum bandwidth allowed during a post-copy migration phase.
numatune
Syntax:
numatune domain [--mode mode] [--nodeset nodeset]
[[--config] [--live] | [--current]]Set or get a domain's numa parameters, corresponding to the <numatune> element of domain XML. Without flags, the current settings are displayed.
mode can be one of `strict', `interleave', `preferred' and 'restrictive' or any valid number from the virDomainNumatuneMemMode enum in case the daemon supports it. For a running domain, the mode can't be changed, and the nodeset can be changed only if the domain was started with `restrictive' mode.
nodeset is a list of numa nodes used by the host for running the domain. Its syntax is a comma separated list, with '-' for ranges and '^' for excluding a node.
If --live is specified, set scheduler information of a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest.
For running guests in Linux hosts, the changes made in the domain's numa parameters does not imply that the guest memory will be moved to a different nodeset immediately. The memory migration depends on the guest activity, and the memory of an idle guest will remain in its previous nodeset for longer. The presence of VFIO devices will also lock parts of the guest memory in the same nodeset used to start the guest, regardless of nodeset changes.
perf
Syntax:
perf domain [--enable eventSpec] [--disable eventSpec]
[[--config] [--live] | [--current]]Get the current perf events setting or enable/disable specific perf events for a guest domain.
Perf is a performance analyzing tool in Linux, and it can instrument CPU performance counters, tracepoints, kprobes, and uprobes (dynamic tracing). Perf supports a list of measurable events, and can measure events coming from different sources. For instance, some event are pure kernel counters, in this case they are called software events, including context-switches, minor-faults, etc.. Now dozens of events from different sources can be supported by perf.
Currently only QEMU/KVM supports this command. The --enable and --disable option combined with eventSpec can be used to enable or disable specific performance event. eventSpec is a string list of one or more events separated by commas. Valid event names are as follows:
Valid perf event names
cmt- A PQos (Platform Qos) feature to monitor the usage of cache by applications running on the platform.mbmt- Provides a way to monitor the total system memory bandwidth between one level of cache and another.mbml- Provides a way to limit the amount of data (bytes/s) send through the memory controller on the socket.cache_misses- Provides the count of cache misses by applications running on the platform.cache_references- Provides the count of cache hits by applications running on th e platform.instructions- Provides the count of instructions executed by applications running on the platform.cpu_cycles- Provides the count of cpu cycles (total/elapsed). May be used with instructions in order to get a cycles per instruction.branch_instructions- Provides the count of branch instructions executed by applications running on the platform.branch_misses- Provides the count of branch misses executed by applications running on the platform.bus_cycles- Provides the count of bus cycles executed by applications running on the platform.stalled_cycles_frontend- Provides the count of stalled cpu cycles in the frontend of the instruction processor pipeline by applications running on the platform.stalled_cycles_backend- Provides the count of stalled cpu cycles in the backend of the instruction processor pipeline by applications running on the platform.ref_cpu_cycles- Provides the count of total cpu cycles not affected by CPU frequency scaling by applications running on the platform.cpu_clock- Provides the cpu clock time consumed by applications running on the platform.task_clock- Provides the task clock time consumed by applications running on the platform.page_faults- Provides the count of page faults by applications running on the platform.context_switches- Provides the count of context switches by applications running on the platform.cpu_migrations- Provides the count cpu migrations by applications running on the platform.page_faults_min- Provides the count minor page faults by applications running on the platform.page_faults_maj- Provides the count major page faults by applications running on the platform.alignment_faults- Provides the count alignment faults by applications running on the platform.emulation_faults- Provides the count emulation faults by applications running on the platform.
Note: The statistics can be retrieved using the domstats command using the --perf flag.
If --live is specified, affect a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. If no flag is specified, behavior is different depending on hypervisor.
reboot
Syntax:
reboot domain [--mode MODE-LIST]Reboot a domain. This acts just as if the domain had the reboot command run from the console. The command returns as soon as it has executed the reboot action, which may be significantly before the domain actually reboots.
The exact behavior of a domain when it reboots is set by the on_reboot parameter in the domain's XML definition.
By default the hypervisor will try to pick a suitable shutdown method. To specify an alternative method, the --mode parameter can specify a comma separated list which includes acpi, agent, initctl, signal and paravirt. The order in which drivers will try each mode is undefined, and not related to the order specified to virsh. For strict control over ordering, use a single mode at a time and repeat the command.
reset
Syntax:
reset domainReset a domain immediately without any guest shutdown. reset emulates the power reset button on a machine, where all guest hardware sees the RST line set and reinitializes internal state.
Note: Reset without any guest OS shutdown risks data loss.
restore
Syntax:
restore state-file [--bypass-cache] [--xml file]
[{--running | --paused}] [--reset-nvram]Restores a domain from a virsh save state file. See save for more info.
If --bypass-cache is specified, the restore will avoid the file system cache, although this may slow down the operation.
--xml file is usually omitted, but can be used to supply an alternative XML file for use on the restored guest with changes only in the host-specific portions of the domain XML. For example, it can be used to account for file naming differences in underlying storage due to disk snapshots taken after the guest was saved.
Normally, restoring a saved image will use the state recorded in the save image to decide between running or paused; passing either the --running or --paused flag will allow overriding which state the domain should be started in.
If --reset-nvram is specified, any existing NVRAM file will be deleted and re-initialized from its pristine template.
Note: To avoid corrupting file system contents within the domain, you should not reuse the saved state file for a second restore unless you have also reverted all storage volumes back to the same contents as when the state file was created.
resume
Syntax:
resume domainMoves a domain out of the suspended state. This will allow a previously suspended domain to now be eligible for scheduling by the underlying hypervisor.
save
Syntax:
save domain state-file [--bypass-cache] [--xml file]
[{--running | --paused}] [--verbose]Saves a running domain (RAM, but not disk state) to a state file so that it can be restored later. Once saved, the domain will no longer be running on the system, thus the memory allocated for the domain will be free for other domains to use. virsh restore restores from this state file. If --bypass-cache is specified, the save will avoid the file system cache, although this may slow down the operation.
The progress may be monitored using domjobinfo virsh command and canceled with domjobabort command (sent by another virsh instance). Another option is to send SIGINT (usually with Ctrl-C) to the virsh process running save command. --verbose displays the progress of save.
This is roughly equivalent to doing a hibernate on a running computer, with all the same limitations. Open network connections may be severed upon restore, as TCP timeouts may have expired.
--xml file is usually omitted, but can be used to supply an alternative XML file for use on the restored guest with changes only in the host-specific portions of the domain XML. For example, it can be used to account for file naming differences that are planned to be made via disk snapshots of underlying storage after the guest is saved.
Normally, restoring a saved image will decide between running or paused based on the state the domain was in when the save was done; passing either the --running or --paused flag will allow overriding which state the restore should use.
Domain saved state files assume that disk images will be unchanged between the creation and restore point. For a more complete system restore point, where the disk state is saved alongside the memory state, see the snapshot family of commands.
save-image-define
Syntax:
save-image-define file xml [{--running | --paused}]Update the domain XML that will be used when file is later used in the restore command. The xml argument must be a file name containing the alternative XML, with changes only in the host-specific portions of the domain XML. For example, it can be used to account for file naming differences resulting from creating disk snapshots of underlying storage after the guest was saved.
The save image records whether the domain should be restored to a running or paused state. Normally, this command does not alter the recorded state; passing either the --running or --paused flag will allow overriding which state the restore should use.
save-image-dumpxml
Syntax:
save-image-dumpxml file [--security-info]Extract the domain XML that was in effect at the time the saved state file file was created with the save command. Using --security-info will also include security sensitive information.
save-image-edit
Syntax:
save-image-edit file [{--running | --paused}]Edit the XML configuration associated with a saved state file file created by the save command.
The save image records whether the domain should be restored to a running or paused state. Normally, this command does not alter the recorded state; passing either the --running or --paused flag will allow overriding which state the restore should use.
This is equivalent to:
virsh save-image-dumpxml state-file > state-file.xml
vi state-file.xml (or make changes with your other text editor)
virsh save-image-define state-file state-file-xmlexcept that it does some error checking.
The editor used can be supplied by the $VISUAL or $EDITOR environment variables, and defaults to vi.
schedinfo
Syntax:
schedinfo domain [[--config] [--live] | [--current]] [[--set] parameter=value]...
schedinfo [--weight number] [--cap number] domainAllows you to show (and set) the domain scheduler parameters. The parameters available for each hypervisor are:
LXC (posix scheduler) : cpu_shares, vcpu_period, vcpu_quota
QEMU/KVM (posix scheduler): cpu_shares, vcpu_period, vcpu_quota, emulator_period, emulator_quota, global_period, global_quota, iothread_period, iothread_quota
Xen (credit scheduler): weight, cap
ESX (allocation scheduler): reservation, limit, shares
If --live is specified, set scheduler information of a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest.
Note: The cpu_shares parameter has a valid value range of 2-262144.
Note: The weight and cap parameters are defined only for the XEN_CREDIT scheduler.
Note: The vcpu_period, emulator_period, and iothread_period parameters have a valid value range of 1000-1000000 or 0, and the vcpu_quota, emulator_quota, and iothread_quota parameters have a valid value range of 1000-17592186044415 or less than 0. The value 0 for either parameter is the same as not specifying that parameter.
screenshot
Syntax:
screenshot domain [imagefilepath] [--screen screenID]Takes a screenshot of a current domain console and stores it into a file. Optionally, if the hypervisor supports more displays for a domain, screenID allows specifying which screen will be captured. It is the sequential number of screen. In case of multiple graphics cards, heads are enumerated before devices, e.g. having two graphics cards, both with four heads, screen ID 5 addresses the second head on the second card.
send-key
Syntax:
send-key domain [--codeset codeset] [--holdtime holdtime] keycode...Parse the keycode sequence as keystrokes to send to domain. Each keycode can either be a numeric value or a symbolic name from the corresponding codeset. If --holdtime is given, each keystroke will be held for that many milliseconds. The default codeset is linux, but use of the --codeset option allows other codesets to be chosen.
If multiple keycodes are specified, they are all sent simultaneously to the guest, and they may be received in random order. If you need distinct keypresses, you must use multiple send-key invocations.
linuxThe numeric values are those defined by the Linux generic input event subsystem. The symbolic names match the corresponding Linux key constant macro names.
See virkeycode-linux(7) and virkeyname-linux(7)
xtThe numeric values are those defined by the original XT keyboard controller. No symbolic names are provided
See virkeycode-xt(7)
atset1The numeric values are those defined by the AT keyboard controller, set 1 (aka XT compatible set). Extended keycoes from
atset1may differ from extended keycodes in thextcodeset. No symbolic names are providedSee virkeycode-atset1(7)
atset2The numeric values are those defined by the AT keyboard controller, set 2. No symbolic names are provided
See virkeycode-atset2(7)
atset3The numeric values are those defined by the AT keyboard controller, set 3 (aka PS/2 compatible set). No symbolic names are provided
See virkeycode-atset3(7)
os_xThe numeric values are those defined by the macOS keyboard input subsystem. The symbolic names match the corresponding macOS key constant macro names
See virkeycode-osx(7) and virkeyname-osx(7)
xt_kbdThe numeric values are those defined by the Linux KBD device. These are a variant on the original XT codeset, but often with different encoding for extended keycodes. No symbolic names are provided.
See virkeycode-xtkbd(7)
win32The numeric values are those defined by the Win32 keyboard input subsystem. The symbolic names match the corresponding Win32 key constant macro names
See virkeycode-win32(7) and virkeyname-win32(7)
usbThe numeric values are those defined by the USB HID specification for keyboard input. No symbolic names are provided
See virkeycode-usb(7)
qnumThe numeric values are those defined by the QNUM extension for sending raw keycodes. These are a variant on the XT codeset, but extended keycodes have the low bit of the second byte set, instead of the high bit of the first byte. No symbolic names are provided.
See virkeycode-qnum(7)
Examples:
# send three strokes 'k', 'e', 'y', using xt codeset. these
# are all pressed simultaneously and may be received by the guest
# in random order
virsh send-key dom --codeset xt 37 18 21
# send one stroke 'right-ctrl+C'
virsh send-key dom KEY_RIGHTCTRL KEY_C
# send a tab, held for 1 second
virsh send-key --holdtime 1000 0xfsend-process-signal
Syntax:
send-process-signal domain-id pid signameSend a signal signame to the process identified by pid running in the virtual domain domain-id. The pid is a process ID in the virtual domain namespace.
The signame argument may be either an integer signal constant number, or one of the symbolic names:
"nop", "hup", "int", "quit", "ill",
"trap", "abrt", "bus", "fpe", "kill",
"usr1", "segv", "usr2", "pipe", "alrm",
"term", "stkflt", "chld", "cont", "stop",
"tstp", "ttin", "ttou", "urg", "xcpu",
"xfsz", "vtalrm", "prof", "winch", "poll",
"pwr", "sys", "rt0", "rt1", "rt2", "rt3",
"rt4", "rt5", "rt6", "rt7", "rt8", "rt9",
"rt10", "rt11", "rt12", "rt13", "rt14", "rt15",
"rt16", "rt17", "rt18", "rt19", "rt20", "rt21",
"rt22", "rt23", "rt24", "rt25", "rt26", "rt27",
"rt28", "rt29", "rt30", "rt31", "rt32"The symbol name may optionally be prefixed with sig or sig_ and may be in uppercase or lowercase.
Examples:
virsh send-process-signal myguest 1 15
virsh send-process-signal myguest 1 term
virsh send-process-signal myguest 1 sigterm
virsh send-process-signal myguest 1 SIG_HUPset-lifecycle-action
Syntax:
set-lifecycle-action domain type action
[[--config] [--live] | [--current]]Set the lifecycle action for specified lifecycle type. The valid types are "poweroff", "reboot" and "crash", and for each of them valid action is one of "destroy", "restart", "rename-restart", "preserve". For type "crash", additional actions "coredump-destroy" and "coredump-restart" are supported.
set-user-password
Syntax:
set-user-password domain user password [--encrypted]Set the password for the user account in the guest domain.
If --encrypted is specified, the password is assumed to be already encrypted by the method required by the guest OS.
For QEMU/KVM, this requires the guest agent to be configured and running.
set-user-sshkeys
Syntax:
set-user-sshkeys domain user [--file FILE] [{--reset | --remove}]Append keys read from FILE into user's SSH authorized keys file in the guest domain. In the FILE keys must be on separate lines and each line must follow authorized keys format as defined by sshd(8).
If --reset is specified, then the guest authorized keys file content is removed before appending new keys. As a special case, if --reset is provided and no FILE was provided then no new keys are added and the authorized keys file is cleared out.
If --remove is specified, then instead of adding any new keys then keys read from FILE are removed from the authorized keys file. It is not considered an error if the key does not exist in the file.
setmaxmem
Syntax:
setmaxmem domain size [[--config] [--live] | [--current]]Change the maximum memory allocation limit for a guest domain. If --live is specified, affect a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. If no flag is specified, behavior is different depending on hypervisor.
Some hypervisors such as QEMU/KVM don't support live changes (especially increasing) of the maximum memory limit. Even persistent configuration changes might not be performed with some hypervisors/configuration (e.g. on NUMA enabled domains on QEMU). For complex configuration changes use command edit instead).
size is a scaled integer (see NOTES above); it defaults to kibibytes (blocks of 1024 bytes) unless you provide a suffix (and the older option name --kilobytes is available as a deprecated synonym) . Libvirt rounds up to the nearest kibibyte. Some hypervisors require a larger granularity than KiB, and requests that are not an even multiple will be rounded up. For example, vSphere/ESX rounds the parameter up to mebibytes (1024 kibibytes).
setmem
Syntax:
setmem domain size [[--config] [--live] | [--current]]Change the memory allocation for a guest domain. If --live is specified, perform a memory balloon of a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. If no flag is specified, behavior is different depending on hypervisor.
size is a scaled integer (see NOTES above); it defaults to kibibytes (blocks of 1024 bytes) unless you provide a suffix (and the older option name --kilobytes is available as a deprecated synonym) . Libvirt rounds up to the nearest kibibyte. Some hypervisors require a larger granularity than KiB, and requests that are not an even multiple will be rounded up. For example, vSphere/ESX rounds the parameter up to mebibytes (1024 kibibytes).
For Xen, you can only adjust the memory of a running domain if the domain is paravirtualized or running the PV balloon driver.
For LXC, the value being set is the cgroups value for limit_in_bytes or the maximum amount of user memory (including file cache). When viewing memory inside the container, this is the /proc/meminfo "MemTotal" value. When viewing the value from the host, use the virsh memtune command. In order to view the current memory in use and the maximum value allowed to set memory, use the virsh dominfo command.
setvcpus
Syntax:
setvcpus domain count [--maximum] [[--config] [--live] | [--current]] [--guest] [--hotpluggable]Change the number of virtual CPUs active in a guest domain. By default, this command works on active guest domains. To change the settings for an inactive guest domain, use the --config flag.
The count value may be limited by host, hypervisor, or a limit coming from the original description of the guest domain. For Xen, you can only adjust the virtual CPUs of a running domain if the domain is paravirtualized.
If the --config flag is specified, the change is made to the stored XML configuration for the guest domain, and will only take effect when the guest domain is next started.
If --live is specified, the guest domain must be active, and the change takes place immediately. Both the --config and --live flags may be specified together if supported by the hypervisor. If this command is run before the guest has finished booting, the guest may fail to process the change.
If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest.
When no flags are given, the --live flag is assumed and the guest domain must be active. In this situation it is up to the hypervisor whether the --config flag is also assumed, and therefore whether the XML configuration is adjusted to make the change persistent.
If --guest is specified, then the count of cpus is modified in the guest instead of the hypervisor. This flag is usable only for live domains and may require guest agent to be configured in the guest.
To allow adding vcpus to persistent definitions that can be later hotunplugged after the domain is booted it is necessary to specify the --hotpluggable flag. Vcpus added to live domains supporting vcpu unplug are automatically marked as hotpluggable.
The --maximum flag controls the maximum number of virtual cpus that can be hot-plugged the next time the domain is booted. As such, it must only be used with the --config flag, and not with the --live or the --current flag. Note that it may not be possible to change the maximum vcpu count if the processor topology is specified for the guest.
setvcpu
Syntax:
setvcpu domain vcpulist [--enable] | [--disable]
[[--live] [--config] | [--current]]Change state of individual vCPUs using hot(un)plug mechanism.
See vcpupin for information on format of vcpulist. Hypervisor drivers may require that vcpulist contains exactly vCPUs belonging to one hotpluggable entity. This is usually just a single vCPU but certain architectures such as ppc64 require a full core to be specified at once.
Note that hypervisors may refuse to disable certain vcpus such as vcpu 0 or others.
If --live is specified, affect a running domain. If --config is specified, affect the next startup of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. This is the default. Both --live and --config flags may be given, but --current is exclusive.
shutdown
Syntax:
shutdown domain [--mode MODE-LIST]Gracefully shuts down a domain. This coordinates with the domain OS to perform graceful shutdown, so there is no guarantee that it will succeed, and may take a variable length of time depending on what services must be shutdown in the domain.
The exact behavior of a domain when it shuts down is set by the on_poweroff parameter in the domain's XML definition.
If domain is transient, then the metadata of any snapshots and checkpoints will be lost once the guest stops running, but the underlying contents still exist, and a new domain with the same name and UUID can restore the snapshot metadata with snapshot-create, and the checkpoint metadata with checkpoint-create.
By default the hypervisor will try to pick a suitable shutdown method. To specify an alternative method, the --mode parameter can specify a comma separated list which includes acpi, agent, initctl, signal and paravirt. The order in which drivers will try each mode is undefined, and not related to the order specified to virsh. For strict control over ordering, use a single mode at a time and repeat the command.
start
Syntax:
start domain-name-or-uuid [--console] [--paused]
[--autodestroy] [--bypass-cache] [--force-boot]
[--pass-fds N,M,...] [--reset-nvram]Start a (previously defined) inactive domain, either from the last managedsave state, or via a fresh boot if no managedsave state is present. The domain will be paused if the --paused option is used and supported by the driver; otherwise it will be running. If --console is requested, attach to the console after creation. If --autodestroy is requested, then the guest will be automatically destroyed when virsh closes its connection to libvirt, or otherwise exits. If --bypass-cache is specified, and managedsave state exists, the restore will avoid the file system cache, although this may slow down the operation. If --force-boot is specified, then any managedsave state is discarded and a fresh boot occurs.
If --pass-fds is specified, the argument is a comma separated list of open file descriptors which should be pass on into the guest. The file descriptors will be re-numbered in the guest, starting from 3. This is only supported with container based virtualization.
If --reset-nvram is specified, any existing NVRAM file will be deleted and re-initialized from its pristine template.
suspend
Syntax:
suspend domainSuspend a running domain. It is kept in memory but won't be scheduled anymore.
ttyconsole
Syntax:
ttyconsole domainOutput the device used for the TTY console of the domain. If the information is not available the processes will provide an exit code of 1.
undefine
Syntax:
undefine domain [--managed-save] [--snapshots-metadata]
[--checkpoints-metadata] [--nvram] [--keep-nvram]
[ {--storage volumes | --remove-all-storage
[--delete-storage-volume-snapshots]} --wipe-storage]Undefine a domain. If the domain is running, this converts it to a transient domain, without stopping it. If the domain is inactive, the domain configuration is removed.
The --managed-save flag guarantees that any managed save image (see the managedsave command) is also cleaned up. Without the flag, attempts to undefine a domain with a managed save image will fail.
The --snapshots-metadata flag guarantees that any snapshots (see the snapshot-list command) are also cleaned up when undefining an inactive domain. Without the flag, attempts to undefine an inactive domain with snapshot metadata will fail. If the domain is active, this flag is ignored.
The --checkpoints-metadata flag guarantees that any checkpoints (see the checkpoint-list command) are also cleaned up when undefining an inactive domain. Without the flag, attempts to undefine an inactive domain with checkpoint metadata will fail. If the domain is active, this flag is ignored.
--nvram and --keep-nvram specify accordingly to delete or keep nvram (/domain/os/nvram/) file. If the domain has an nvram file and the flags are omitted, the undefine will fail.
The --storage flag takes a parameter volumes, which is a comma separated list of volume target names or source paths of storage volumes to be removed along with the undefined domain. Volumes can be undefined and thus removed only on inactive domains. Volume deletion is only attempted after the domain is undefined; if not all of the requested volumes could be deleted, the error message indicates what still remains behind. If a volume path is not found in the domain definition, it's treated as if the volume was successfully deleted. Only volumes managed by libvirt in storage pools can be removed this way. (See domblklist for list of target names associated to a domain). Example: --storage vda,/path/to/storage.img
The --remove-all-storage flag specifies that all of the domain's storage volumes should be deleted.
The --delete-storage-volume-snapshots (previously --delete-snapshots) flag specifies that any snapshots associated with the storage volume should be deleted as well. Requires the --remove-all-storage flag to be provided. Not all storage drivers support this option, presently only rbd. Using this when also removing volumes handled by a storage driver which does not support the flag will result in failure.
The flag --wipe-storage specifies that the storage volumes should be wiped before removal.
NOTE: For an inactive domain, the domain name or UUID must be used as the domain.
vcpucount
Syntax:
vcpucount domain [{--maximum | --active}
{--config | --live | --current}] [--guest]Print information about the virtual cpu counts of the given domain. If no flags are specified, all possible counts are listed in a table; otherwise, the output is limited to just the numeric value requested. For historical reasons, the table lists the label "current" on the rows that can be queried in isolation via the --active flag, rather than relating to the --current flag.
--maximum requests information on the maximum cap of vcpus that a domain can add via setvcpus, while --active shows the current usage; these two flags cannot both be specified. --config requires a persistent guest and requests information regarding the next time the domain will be booted, --live requires a running domain and lists current values, and --current queries according to the current state of the domain (corresponding to --live if running, or --config if inactive); these three flags are mutually exclusive.
If --guest is specified, then the count of cpus is reported from the perspective of the guest. This flag is usable only for live domains and may require guest agent to be configured in the guest.
vcpuinfo
Syntax:
vcpuinfo domain [--pretty]Returns basic information about the domain virtual CPUs, like the number of vCPUs, the running time, the affinity to physical processors.
With --pretty, cpu affinities are shown as ranges.
Example:
$ virsh vcpuinfo fedora
VCPU: 0
CPU: 0
State: running
CPU time: 7,0s
CPU Affinity: yyyy
VCPU: 1
CPU: 1
State: running
CPU time: 0,7s
CPU Affinity: yyyySTATES
The State field displays the current operating state of a virtual CPU
offlineThe virtual CPU is offline and not usable by the domain. This state is not supported by all hypervisors.
runningThe virtual CPU is available to the domain and is operating.
blockedThe virtual CPU is available to the domain but is waiting for a resource. This state is not supported by all hypervisors, in which case running may be reported instead.
no stateThe virtual CPU state could not be determined. This could happen if the hypervisor is newer than virsh.
N/AThere's no information about the virtual CPU state available. This can be the case if the domain is not running or the hypervisor does not report the virtual CPU state.
vcpupin
Syntax:
vcpupin domain [vcpu] [cpulist] [[--live] [--config] | [--current]]Query or change the pinning of domain VCPUs to host physical CPUs. To pin a single vcpu, specify cpulist; otherwise, you can query one vcpu or omit vcpu to list all at once.
cpulist is a list of physical CPU numbers. Its syntax is a comma separated list and a special markup using '-' and '^' (ex. '0-4', '0-3,^2') can also be allowed. The '-' denotes the range and the '^' denotes exclusive. For pinning the vcpu to all physical cpus specify 'r' as a cpulist. If --live is specified, affect a running guest. If --config is specified, affect the next start of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given if cpulist is present, but --current is exclusive. If no flag is specified, behavior is different depending on hypervisor.
Note: The expression is sequentially evaluated, so "0-15,^8" is identical to "9-14,0-7,15" but not identical to "^8,0-15".
vncdisplay
Syntax:
vncdisplay domainOutput the IP address and port number for the VNC display. If the information is not available the processes will provide an exit code of 1.
DEVICE COMMANDS
The following commands manipulate devices associated to domains. The domain can be specified as a short integer, a name or a full UUID. To better understand the values allowed as options for the command reading the documentation at https://libvirt.org/formatdomain.html on the format of the device sections to get the most accurate set of accepted values.
attach-device
Syntax:
attach-device domain FILE [[[--live] [--config] | [--current]] | [--persistent]]Attach a device to the domain, using a device definition in an XML file using a device definition element such as <disk> or <interface> as the top-level element. See the documentation at https://libvirt.org/formatdomain.html#elementsDevices to learn about libvirt XML format for a device. If --config is specified the command alters the persistent guest configuration with the device attach taking effect the next time libvirt starts the domain. For cdrom and floppy devices, this command only replaces the media within an existing device; consider using update-device for this usage. For passthrough host devices, see also nodedev-detach, needed if the PCI device does not use managed mode.
If --live is specified, affect a running domain. If --config is specified, affect the next startup of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. When no flag is specified legacy API is used whose behavior depends on the hypervisor driver.
For compatibility purposes, --persistent behaves like --config for an offline domain, and like --live --config for a running domain.
Note: using of partial device definition XML files may lead to unexpected results as some fields may be autogenerated and thus match devices other than expected.
attach-disk
Syntax:
attach-disk domain source target [[[--live] [--config] |
[--current]] | [--persistent]] [--targetbus bus]
[--driver driver] [--subdriver subdriver] [--iothread iothread]
[--cache cache] [--io io] [--type type] [--alias alias]
[--mode mode] [--sourcetype sourcetype]
[--source-protocol protocol] [--source-host-name hostname:port]
[--source-host-transport transport] [--source-host-socket socket]
[--serial serial] [--wwn wwn] [--rawio] [--address address]
[--multifunction] [--print-xml]Attach a new disk device to the domain. source is path for the files and devices unless --source-protocol is specified, in which case source is the name of a network disk. target controls the bus or device under which the disk is exposed to the guest OS. It indicates the "logical" device name; the optional targetbus attribute specifies the type of disk device to emulate; possible values are driver specific, with typical values being ide, scsi, virtio, xen, usb, sata, or sd, if omitted, the bus type is inferred from the style of the device name (e.g. a device named 'sda' will typically be exported using a SCSI bus). driver can be file, tap or phy for the Xen hypervisor depending on the kind of access; or qemu for the QEMU emulator. Further details to the driver can be passed using subdriver. For Xen subdriver can be aio, while for QEMU subdriver should match the format of the disk source, such as raw or qcow2. Hypervisor default will be used if subdriver is not specified. However, the default may not be correct, esp. for QEMU as for security reasons it is configured not to detect disk formats. type can indicate lun, cdrom or floppy as alternative to the disk default, although this use only replaces the media within the existing virtual cdrom or floppy device; consider using update-device for this usage instead. alias can set user supplied alias. mode can specify the two specific mode readonly or shareable. sourcetype can indicate the type of source (blocknetwork) cache can be one of "default", "none", "writethrough", "writeback", "directsync" or "unsafe". io controls specific policies on I/O; QEMU guests support "threads", "native" and "io_uring". iothread is the number within the range of domain IOThreads to which this disk may be attached (QEMU only). serial is the serial of disk device. wwn is the wwn of disk device. rawio indicates the disk needs rawio capability. address is the address of disk device in the form of pci:domain.bus.slot.function, scsi:controller.bus.unit, ide:controller.bus.unit, usb:bus.port, sata:controller.bus.unit or ccw:cssid.ssid.devno. Virtio-ccw devices must have their cssid set to 0xfe. multifunction indicates specified pci address is a multifunction pci device address.
There is also support for using a network disk. As specified, the user can provide a --source-protocol in which case the source parameter will be interpreted as the source name. --source-protocol must be provided if the user intends to provide a network disk or host information. Host information can be provided using the tags --source-host-name, --source-host-transport, and --source-host-socket, which respectively denote the name of the host, the host's transport method, and the socket that the host uses. --source-host-socket and --source-host-name cannot both be provided, and the user must provide a --source-host-transport if they want to provide a --source-host-socket. The --source-host-name parameter supports host:port syntax if the user wants to provide a port as well.
If --print-xml is specified, then the XML of the disk that would be attached is printed instead.
If --live is specified, affect a running domain. If --config is specified, affect the next startup of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. When no flag is specified legacy API is used whose behavior depends on the hypervisor driver.
For compatibility purposes, --persistent behaves like --config for an offline domain, and like --live --config for a running domain. Likewise, --shareable is an alias for --mode shareable.
attach-interface
Syntax:
attach-interface domain type source [[[--live]
[--config] | [--current]] | [--persistent]]
[--target target] [--mac mac] [--script script] [--model model]
[--inbound average,peak,burst,floor] [--outbound average,peak,burst]
[--alias alias] [--managed] [--print-xml]
[--source-mode mode]Attach a new network interface to the domain.
type can be one of the:
network to indicate connection via a libvirt virtual network,
bridge to indicate connection via a bridge device on the host,
direct to indicate connection directly to one of the host's network interfaces or bridges,
hostdev to indicate connection using a passthrough of PCI device on the host,
vhostuser to indicate connection using a virtio transport protocol.
source indicates the source of the connection. The source depends on the type of the interface:
network name of the virtual network,
bridge the name of the bridge device,
direct the name of the host's interface or bridge,
hostdev the PCI address of the host's interface formatted as domain🚌slot.function.
vhostuser the path to UNIX socket (control plane)
--target is used to specify the tap/macvtap device to be used to connect the domain to the source. Names starting with 'vnet' are considered as auto-generated and are blanked out/regenerated each time the interface is attached.
--mac specifies the MAC address of the network interface; if a MAC address is not given, a new address will be automatically generated (and stored in the persistent configuration if "--config" is given on the command line).
--script is used to specify a path to a custom script to be called while attaching to a bridge - this will be called instead of the default script not in addition to it. This is valid only for interfaces of bridge type and only for Xen domains.
--model specifies the network device model to be presented to the domain.
alias can set user supplied alias.
--inbound and --outbound control the bandwidth of the interface. At least one from the average, floor pair must be specified. The other two peak and burst are optional, so "average,peak", "average,,burst", "average,,,floor", "average" and ",,,floor" are also legal. Values for average, floor and peak are expressed in kilobytes per second, while burst is expressed in kilobytes in a single burst at peak speed as described in the Network XML documentation at https://libvirt.org/formatnetwork.html#elementQoS.
--managed is usable only for hostdev type and tells libvirt that the interface should be managed, which means detached and reattached from/to the host by libvirt.
--source-mode is mandatory for vhostuser interface and accepts values server and client that control whether hypervisor waits for the other process to connect, or initiates connection, respectively.
If --print-xml is specified, then the XML of the interface that would be attached is printed instead.
If --live is specified, affect a running domain. If --config is specified, affect the next startup of a persistent guest. If --current is specified, affect the current domain state, which can either be live or offline. Both --live and --config flags may be given, but --current is exclusive. When no flag is specified legacy API is used whose behavior depends on the hypervisor driver.
For compatibility purposes, --persistent behaves like --config for an offline domain, and like --live --config for a running domain.
Note: the optional target value is the name of a device to be created as the back-end on the node. If not provided a device named "vnetN" or "vifN" will be created automatically.
detach-device
Syntax:
detach-device domain FILE [[[--live] [--config] |
[--current]] | [--persistent]]Detach a device from the domain, takes the same kind of XML descriptions as command attach-device. For passthrough host devices, see also nodedev-reattach, needed if the device does not use managed mode.
Note: The supplied XML description of the device should be as specific as its definition in the domain XML. The set of attributes used to match the device are internal to the drivers. Using a partial definition, or attempting to detach a device that is not present in the domain XML, but shares some specific attributes with one that is present, may lead to unexpected results.
Quirk: Device unplug is asynchronous in most cases and requires guest cooperation. This means that it's up to the discretion of the guest to disallow or delay the unplug arbitrarily. As the libvirt API used in this command was designed as synchronous it returns success after some timeout even if the device was not unplugged yet to allow further interactions with the domain e.g. if the guest is unresponsive. Callers which need to make sure that the device was unplugged can use libvirt events (see virsh event) to be notified when the device is removed. Note that the event may arrive before the command returns.
If --live is specified, affect a running domain. If --config is specified, affect the next startup of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. When no flag is specified legacy API is used whose behavior depends on the hypervisor driver.
For compatibility purposes, --persistent behaves like --config for an offline domain, and like --live --config for a running domain.
Note that older versions of virsh used --config as an alias for --persistent.
detach-device-alias
Syntax:
detach-device-alias domain alias [[[--live] [--config] | [--current]]]]Detach a device with given alias from the domain. This command returns successfully after the unplug request was sent to the hypervisor. The actual removal of the device is notified asynchronously via libvirt events (see virsh event).
If --live is specified, affect a running domain. If --config is specified, affect the next startup of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive.
detach-disk
Syntax:
detach-disk domain target [[[--live] [--config] |
[--current]] | [--persistent]] [--print-xml]Detach a disk device from a domain. The target is the device as seen from the domain.
If --live is specified, affect a running domain. If --config is specified, affect the next startup of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. When no flag is specified legacy API is used whose behavior depends on the hypervisor driver.
For compatibility purposes, --persistent behaves like --config for an offline domain, and like --live --config for a running domain.
Note that older versions of virsh used --config as an alias for --persistent.
If --print-xml is specified, then the XML which would be used to detach the disk is printed instead.
Please see documentation for detach-device for known quirks.
detach-interface
Syntax:
detach-interface domain type [--mac mac]
[[[--live] [--config] | [--current]] | [--persistent]]Detach a network interface from a domain. type can be either network to indicate a physical network device or bridge to indicate a bridge to a device. It is recommended to use the mac option to distinguish between the interfaces if more than one are present on the domain.
If --live is specified, affect a running domain. If --config is specified, affect the next startup of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. When no flag is specified legacy API is used whose behavior depends on the hypervisor driver.
For compatibility purposes, --persistent behaves like --config for an offline domain, and like --live --config for a running domain.
Note that older versions of virsh used --config as an alias for --persistent.
Please see documentation for detach-device for known quirks.
update-device
Syntax:
update-device domain file [--force] [[[--live]
[--config] | [--current]] | [--persistent]]Update the characteristics of a device associated with domain, based on the device definition in an XML file. The --force option can be used to force device update, e.g., to eject a CD-ROM even if it is locked/mounted in the domain. See the documentation at https://libvirt.org/formatdomain.html#elementsDevices to learn about libvirt XML format for a device.
If --live is specified, affect a running domain. If --config is specified, affect the next startup of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. Not specifying any flag is the same as specifying --current.
For compatibility purposes, --persistent behaves like --config for an offline domain, and like --live --config for a running domain.
Note that older versions of virsh used --config as an alias for --persistent.
Note: using of partial device definition XML files may lead to unexpected results as some fields may be autogenerated and thus match devices other than expected.
update-memory-device
Syntax:
update-memory-device domain [--print-xml] [[--alias alias] | [--node node]]
[[--live] [--config] | [--current]]
[--requested-size size]This command finds <memory/> device inside given domain, changes requested values and passes updated device XML to daemon. If --print-xml is specified then the device is not changed, but the updated device XML is printed to stdout. If there are more than one <memory/> devices in domain use --alias or --node to select the desired one.
If --live is specified, affect a running domain. If --config is specified, affect the next startup of a persistent guest. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. Not specifying any flag is the same as specifying --current.
If --requested-size is specified then <requested/> under memory target is changed to requested size (as scaled integer, see NOTES above). It defaults to kibibytes if no suffix is provided. The option is valid only for virtio-mem memory device model.
change-media
Syntax:
change-media domain path [--eject] [--insert]
[--update] [source] [--force] [[--live] [--config] |
[--current]] [--print-xml] [--block]Change media of CDROM or floppy drive. path can be the fully-qualified path or the unique target name (<target dev='hdc'>) of the disk device. source specifies the path of the media to be inserted or updated. The --block flag allows setting the backing type in case a block device is used as media for the CDROM or floppy drive instead of a file.
--eject indicates the media will be ejected. --insert indicates the media will be inserted. source must be specified. If the device has source (e.g. <source file='media'>), and source is not specified, --update is equal to --eject. If the device has no source, and source is specified, --update is equal to --insert. If the device has source, and source is specified, --update behaves like combination of --eject and --insert. If none of --eject, --insert, and --update is specified, --update is used by default. The --force option can be used to force media changing. If --live is specified, alter live configuration of running guest. If --config is specified, alter persistent configuration, effect observed on next startup of the guest. --current can be either or both of live and config, depends on the hypervisor's implementation. Both --live and --config flags may be given, but --current is exclusive. If no flag is specified, behavior is different depending on hypervisor. If --print-xml is specified, the XML that would be used to change media is printed instead of changing the media.
NODEDEV COMMANDS
The following commands manipulate host devices that are intended to be passed through to guest domains via <hostdev> elements in a domain's <devices> section. A node device key is generally specified by the bus name followed by its address, using underscores between all components, such as pci_0000_00_02_1, usb_1_5_3, or net_eth1_00_27_13_6a_fe_00. The nodedev-list gives the full list of host devices that are known to libvirt, although this includes devices that cannot be assigned to a guest (for example, attempting to detach the PCI device that controls the host's hard disk controller where the guest's disk images live could cause the host system to lock up or reboot).
For more information on node device definition see: https://libvirt.org/formatnode.html.
Passthrough devices cannot be simultaneously used by the host and its guest domains, nor by multiple active guests at once. If the <hostdev> description of a PCI device includes the attribute managed='yes', and the hypervisor driver supports it, then the device is in managed mode, and attempts to use that passthrough device in an active guest will automatically behave as if nodedev-detach (guest start, device hot-plug) and nodedev-reattach (guest stop, device hot-unplug) were called at the right points. If a PCI device is not marked as managed, then it must manually be detached before guests can use it, and manually reattached to be returned to the host. Also, if a device is manually detached, then the host does not regain control of the device without a matching reattach, even if the guests use the device in managed mode.
nodedev-create
Syntax:
nodedev-create FILECreate a device on the host node that can then be assigned to virtual machines. Normally, libvirt is able to automatically determine which host nodes are available for use, but this allows registration of host hardware that libvirt did not automatically detect. file contains xml for a top-level <device> description of a node device.
nodedev-destroy
Syntax:
nodedev-destroy deviceDestroy (stop) a device on the host. device can be either device name or wwn pair in "wwnn,wwpn" format (only works for vHBA currently). Note that this makes libvirt quit managing a host device, and may even make that device unusable by the rest of the physical host until a reboot.
nodedev-define
Syntax:
nodedev-define FILEDefine an inactive persistent device or modify an existing persistent one from the XML FILE.
nodedev-undefine
Syntax:
nodedev-undefine deviceUndefine the configuration for a persistent device. If the device is active, make it transient.
nodedev-start
Syntax:
nodedev-start deviceStart a (previously defined) inactive device.
nodedev-detach
Syntax:
nodedev-detach nodedev [--driver backend_driver]Detach nodedev from the host, so that it can safely be used by guests via <hostdev> passthrough. This is reversed with nodedev-reattach, and is done automatically for managed devices.
Different backend drivers expect the device to be bound to different dummy devices. For example, QEMU's "kvm" backend driver (the default) expects the device to be bound to pci-stub, but its "vfio" backend driver expects the device to be bound to vfio-pci. The --driver parameter can be used to specify the desired backend driver.
nodedev-dumpxml
Syntax:
nodedev-dumpxml deviceDump a <device> XML representation for the given node device, including such information as the device name, which bus owns the device, the vendor and product id, and any capabilities of the device usable by libvirt (such as whether device reset is supported). device can be either device name or wwn pair in "wwnn,wwpn" format (only works for HBA).
nodedev-info
Syntax:
nodedev-info deviceReturns basic information about the device object.
nodedev-list
Syntax:
nodedev-list [--cap capability] [--tree] [--inactive | --all]List all of the devices available on the node that are known by libvirt. cap is used to filter the list by capability types, the types must be separated by comma, e.g. --cap pci,scsi. Valid capability types include 'system', 'pci', 'usb_device', 'usb', 'net', 'scsi_host', 'scsi_target', 'scsi', 'storage', 'fc_host', 'vports', 'scsi_generic', 'drm', 'mdev', 'mdev_types', 'ccw', 'css', 'ap_card', 'ap_queue', 'ap_matrix'. By default, only active devices are listed. --inactive is used to list only inactive devices, and -all is used to list both active and inactive devices. If --tree is used, the output is formatted in a tree representing parents of each node. --tree is mutually exclusive with all other options.
nodedev-reattach
Syntax:
nodedev-reattach nodedevDeclare that nodedev is no longer in use by any guests, and that the host can resume normal use of the device. This is done automatically for PCI devices in managed mode and USB devices, but must be done explicitly to match any explicit nodedev-detach.
nodedev-reset
Syntax:
nodedev-reset nodedevTrigger a device reset for nodedev, useful prior to transferring a node device between guest passthrough or the host. Libvirt will often do this action implicitly when required, but this command allows an explicit reset when needed.
nodedev-event
Syntax:
nodedev-event {[nodedev] event [--loop] [--timeout seconds] [--timestamp] | --list}Wait for a class of node device events to occur, and print appropriate details of events as they happen. The events can optionally be filtered by nodedev. Using --list as the only argument will provide a list of possible event values known by this client, although the connection might not allow registering for all these events.
By default, this command is one-shot, and returns success once an event occurs; you can send SIGINT (usually via Ctrl-C) to quit immediately. If --timeout is specified, the command gives up waiting for events after seconds have elapsed. With --loop, the command prints all events until a timeout or interrupt key.
When --timestamp is used, a human-readable timestamp will be printed before the event.
nodedev-autostart
Syntax:
nodedev-autostart [--disable] deviceConfigure a device to be automatically started when the host machine boots or the parent device becomes available. With --disable, the device will be set to manual mode and will no longer be automatically started by the host. This command is only supported for persistently-defined mediated devices.
VIRTUAL NETWORK COMMANDS
The following commands manipulate networks. Libvirt has the capability to define virtual networks which can then be used by domains and linked to actual network devices. For more detailed information about this feature see the documentation at https://libvirt.org/formatnetwork.html . Many of the commands for virtual networks are similar to the ones used for domains, but the way to name a virtual network is either by its name or UUID.
net-autostart
Syntax:
net-autostart network [--disable]Configure a virtual network to be automatically started at boot. The --disable option disable autostarting.
net-create
Syntax:
net-create file [--validate]Create a transient (temporary) virtual network from an XML file and instantiate (start) the network. See the documentation at https://libvirt.org/formatnetwork.html to get a description of the XML network format used by libvirt.
Optionally, the format of the input XML file can be validated against an internal RNG schema with --validate.
net-define
Syntax:
net-define file [--validate]Define an inactive persistent virtual network or modify an existing persistent one from the XML file. Optionally, the format of the input XML file can be validated against an internal RNG schema with --validate.
net-destroy
Syntax:
net-destroy networkDestroy (stop) a given transient or persistent virtual network specified by its name or UUID. This takes effect immediately.
net-dumpxml
Syntax:
net-dumpxml network [--inactive]Output the virtual network information as an XML dump to stdout. If --inactive is specified, then physical functions are not expanded into their associated virtual functions.
net-edit
Syntax:
net-edit networkEdit the XML configuration file for a network.
This is equivalent to:
virsh net-dumpxml --inactive network > network.xml
vi network.xml (or make changes with your other text editor)
virsh net-define network.xmlexcept that it does some error checking.
The editor used can be supplied by the $VISUAL or $EDITOR environment variables, and defaults to vi.
net-event
Syntax:
net-event {[network] event [--loop] [--timeout seconds] [--timestamp] | --list}Wait for a class of network events to occur, and print appropriate details of events as they happen. The events can optionally be filtered by network. Using --list as the only argument will provide a list of possible event values known by this client, although the connection might not allow registering for all these events.
By default, this command is one-shot, and returns success once an event occurs; you can send SIGINT (usually via Ctrl-C) to quit immediately. If --timeout is specified, the command gives up waiting for events after seconds have elapsed. With --loop, the command prints all events until a timeout or interrupt key.
When --timestamp is used, a human-readable timestamp will be printed before the event.
net-info
Syntax:
net-info networkReturns basic information about the network object.
net-list
Syntax:
net-list [--inactive | --all]
{ [--table] | --name | --uuid }
[--persistent] [<--transient>]
[--autostart] [<--no-autostart>]Returns the list of active networks, if --all is specified this will also include defined but inactive networks, if --inactive is specified only the inactive ones will be listed. You may also want to filter the returned networks by --persistent to list the persistent ones, --transient to list the transient ones, --autostart to list the ones with autostart enabled, and --no-autostart to list the ones with autostart disabled.
If --name is specified, network names are printed instead of the table formatted one per line. If --uuid is specified network's UUID's are printed instead of names. Flag --table specifies that the legacy table-formatted output should be used. This is the default. All of these are mutually exclusive.
NOTE: When talking to older servers, this command is forced to use a series of API calls with an inherent race, where a pool might not be listed or might appear more than once if it changed state between calls while the list was being collected. Newer servers do not have this problem.
net-name
Syntax:
net-name network-UUIDConvert a network UUID to network name.
net-start
Syntax:
net-start networkStart a (previously defined) inactive network.
net-undefine
Syntax:
net-undefine networkUndefine the configuration for a persistent network. If the network is active, make it transient.
net-uuid
Syntax:
net-uuid network-nameConvert a network name to network UUID.
net-update
Syntax:
net-update network command section xml
[--parent-index index] [[--live] [--config] | [--current]]Update the given section of an existing network definition, with the changes optionally taking effect immediately, without needing to destroy and re-start the network.
command is one of "add-first", "add-last", "add" (a synonym for add-last), "delete", or "modify".
section is one of "bridge", "domain", "ip", "ip-dhcp-host", "ip-dhcp-range", "forward", "forward-interface", "forward-pf", "portgroup", "dns-host", "dns-txt", or "dns-srv", each section being named by a concatenation of the xml element hierarchy leading to the element being changed. For example, "ip-dhcp-host" will change a <host> element that is contained inside a <dhcp> element inside an <ip> element of the network.
xml is either the text of a complete xml element of the type being changed (e.g. "<host mac="00:11:22:33:44:55' ip='1.2.3.4'/>", or the name of a file that contains a complete xml element. Disambiguation is done by looking at the first character of the provided text - if the first character is "<", it is xml text, if the first character is not "<", it is the name of a file that contains the xml text to be used.
The --parent-index option is used to specify which of several parent elements the requested element is in (0-based). For example, a dhcp <host> element could be in any one of multiple <ip> elements in the network; if a parent-index isn't provided, the "most appropriate" <ip> element will be selected (usually the only one that already has a <dhcp> element), but if --parent-index is given, that particular instance of <ip> will get the modification.
If --live is specified, affect a running network. If --config is specified, affect the next startup of a persistent network. If --current is specified, it is equivalent to either --live or --config, depending on the current state of the guest. Both --live and --config flags may be given, but --current is exclusive. Not specifying any flag is the same as specifying --current.
net-dhcp-leases
Syntax:
net-dhcp-leases network [mac]Get a list of dhcp leases for all network interfaces connected to the given virtual network or limited output just for one interface if mac is specified.
NETWORK PORT COMMANDS
The following commands manipulate network ports. Libvirt virtual networks have ports created when a virtual machine has a virtual network interface added. In general there should be no need to use any of the commands here, since the hypervisor drivers run these commands are the right point in a virtual machine's lifecycle. They can be useful for debugging problems and / or recovering from bugs / stale state.
net-port-list
Syntax:
net-port-list { [--table] | --uuid } networkList all network ports recorded against the network.
If --uuid is specified network ports' UUID's are printed instead of a table. Flag --table specifies that the legacy table-formatted output should be used. This is the default. All of these are mutually exclusive.
net-port-create
Syntax:
net-port-create network file [--validate]Allocate a new network port reserving resources based on the port description. Optionally, the format of the input XML file can be validated against an internal RNG schema with --validate.
net-port-dumpxml
Syntax:
net-port-dumpxml network portOutput the network port information as an XML dump to stdout.
net-port-delete
Syntax:
net-port-delete network portDelete record of the network port and release its resources
INTERFACE COMMANDS
The following commands manipulate host interfaces. Often, these host interfaces can then be used by name within domain <interface> elements (such as a system-created bridge interface), but there is no requirement that host interfaces be tied to any particular guest configuration XML at all.
Many of the commands for host interfaces are similar to the ones used for domains, and the way to name an interface is either by its name or its MAC address. However, using a MAC address for an iface argument only works when that address is unique (if an interface and a bridge share the same MAC address, which is often the case, then using that MAC address results in an error due to ambiguity, and you must resort to a name instead).
iface-bridge
Syntax:
iface-bridge interface bridge [--no-stp] [delay] [--no-start]Create a bridge device named bridge, and attach the existing network device interface to the new bridge. The new bridge defaults to starting immediately, with STP enabled and a delay of 0; these settings can be altered with --no-stp, --no-start, and an integer number of seconds for delay. All IP address configuration of interface will be moved to the new bridge device.
See also iface-unbridge for undoing this operation.
iface-define
Syntax:
iface-define file [--validate]Define an inactive persistent physical host interface or modify an existing persistent one from the XML file. Optionally, the format of the input XML file can be validated against an internal RNG schema with --validate.
iface-destroy
Syntax:
iface-destroy interfaceDestroy (stop) a given host interface, such as by running "if-down" to disable that interface from active use. This takes effect immediately.
iface-dumpxml
Syntax:
iface-dumpxml interface [--inactive]Output the host interface information as an XML dump to stdout. If --inactive is specified, then the output reflects the persistent state of the interface that will be used the next time it is started.
iface-edit
Syntax:
iface-edit interfaceEdit the XML configuration file for a host interface.
This is equivalent to:
virsh iface-dumpxml iface > iface.xml
vi iface.xml (or make changes with your other text editor)
virsh iface-define iface.xmlexcept that it does some error checking.
The editor used can be supplied by the $VISUAL or $EDITOR environment variables, and defaults to vi.
iface-list
Syntax:
iface-list [--inactive | --all]Returns the list of active host interfaces. If --all is specified this will also include defined but inactive interfaces. If --inactive is specified only the inactive ones will be listed.
iface-name
Syntax:
iface-name interfaceConvert a host interface MAC to interface name, if the MAC address is unique among the host's interfaces.
interface specifies the interface MAC address.
iface-mac
Syntax:
iface-mac interfaceConvert a host interface name to MAC address.
interface specifies the interface name.
iface-start
Syntax:
iface-start interfaceStart a (previously defined) host interface, such as by running "if-up".
iface-unbridge
Syntax:
iface-unbridge bridge [--no-start]Tear down a bridge device named bridge, releasing its underlying interface back to normal usage, and moving all IP address configuration from the bridge device to the underlying device. The underlying interface is restarted unless --no-start is present; this flag is present for symmetry, but generally not recommended.
See also iface-bridge for creating a bridge.
iface-undefine
Syntax:
iface-undefine interfaceUndefine the configuration for an inactive host interface.
iface-begin
Syntax:
iface-beginCreate a snapshot of current host interface settings, which can later be committed (iface-commit) or restored (iface-rollback). If a snapshot already exists, then this command will fail until the previous snapshot has been committed or restored. Undefined behavior results if any external changes are made to host interfaces outside of the libvirt API between the beginning of a snapshot and its eventual commit or rollback.
iface-commit
Syntax:
iface-commitDeclare all changes since the last iface-begin as working, and delete the rollback point. If no interface snapshot has already been started, then this command will fail.
iface-rollback
Syntax:
iface-rollbackRevert all host interface settings back to the state recorded in the last iface-begin. If no interface snapshot has already been started, then this command will fail. Rebooting the host also serves as an implicit rollback point.
STORAGE POOL COMMANDS
The following commands manipulate storage pools. Libvirt has the capability to manage various storage solutions, including files, raw partitions, and domain-specific formats, used to provide the storage volumes visible as devices within virtual machines. For more detailed information about this feature, see the documentation at https://libvirt.org/formatstorage.html . Many of the commands for pools are similar to the ones used for domains.
find-storage-pool-sources
Syntax:
find-storage-pool-sources type [srcSpec]Returns XML describing all possible available storage pool sources that could be used to create or define a storage pool of a given type. If srcSpec is provided, it is a file that contains XML to further restrict the query for pools.
Not all storage pools support discovery in this manner. Furthermore, for those that do support discovery, only specific XML elements are required in order to return valid data, while other elements and even attributes of some elements are ignored since they are not necessary to find the pool based on the search criteria. The following lists the supported type options and the expected minimal XML elements used to perform the search.
For a "netfs" or "gluster" pool, the minimal expected XML required is the <host> element with a "name" attribute describing the IP address or hostname to be used to find the pool. The "port" attribute will be ignored as will any other provided XML elements in srcSpec.
For a "logical" pool, the contents of the srcSpec file are ignored, although if provided the file must at least exist.
For an "iscsi" or "iscsi-direct" pool, the minimal expect XML required is the <host> element with a "name" attribute describing the IP address or hostname to be used to find the pool (the iSCSI server address). Optionally, the "port" attribute may be provided, although it will default to 3260. Optionally, an <initiator> XML element with a "name" attribute may be provided to further restrict the iSCSI target search to a specific initiator for multi-iqn iSCSI storage pools.
find-pool-sources-as
Syntax:
find-storage-pool-sources-as type [host] [port] [initiator]Rather than providing srcSpec XML file for find-storage-pool-sources use this command option in order to have virsh generate the query XML file using the optional arguments. The command will return the same output XML as find-storage-pool-sources.
Use host to describe a specific host to use for networked storage, such as netfs, gluster, and iscsi type pools.
Use port to further restrict which networked port to utilize for the connection if required by the specific storage backend, such as iscsi.
Use initiator to further restrict the iscsi type pool searches to specific target initiators.
pool-autostart
Syntax:
pool-autostart pool-or-uuid [--disable]Configure whether pool should automatically start at boot.
pool-build
Syntax:
pool-build pool-or-uuid [--overwrite] [--no-overwrite]Build a given pool.
Options --overwrite and --no-overwrite can only be used for pool-build a filesystem, disk, or logical pool.
For a file system pool if neither flag is specified, then pool-build just makes the target path directory and no attempt to run mkfs on the target volume device. If --no-overwrite is specified, it probes to determine if a filesystem already exists on the target device, returning an error if one exists or using mkfs to format the target device if not. If --overwrite is specified, mkfs is always executed and any existing data on the target device is overwritten unconditionally.
For a disk pool, if neither of them is specified or --no-overwrite is specified, pool-build will check the target volume device for existing filesystems or partitions before attempting to write a new label on the target volume device. If the target volume device already has a label, the command will fail. If --overwrite is specified, then no check will be made on the target volume device prior to writing a new label. Writing of the label uses the pool source format type or "dos" if not specified.
For a logical pool, if neither of them is specified or --no-overwrite is specified, pool-build will check the target volume devices for existing filesystems or partitions before attempting to initialize and format each device for usage by the logical pool. If any target volume device already has a label, the command will fail. If --overwrite is specified, then no check will be made on the target volume devices prior to initializing and formatting each device. Once all the target volume devices are properly formatted via pvcreate, the volume group will be created using all the devices.
pool-create
Syntax:
pool-create file [--build] [[--overwrite] | [--no-overwrite]]Create and start a pool object from the XML file.
[--build] [[--overwrite] | [--no-overwrite]] perform a pool-build after creation in order to remove the need for a follow-up command to build the pool. The --overwrite and --no-overwrite flags follow the same rules as pool-build. If just --build is provided, then pool-build is called with no flags.
pool-create-as
Syntax:
pool-create-as name type
[--source-host hostname] [--source-path path] [--source-dev path]
[--source-name name] [--target path] [--source-format format]
[--source-initiator initiator-iqn]
[--auth-type authtype --auth-username username
[--secret-usage usage | --secret-uuid uuid]]
[--source-protocol-ver ver]
[[--adapter-name name] | [--adapter-wwnn wwnn --adapter-wwpn wwpn]
[--adapter-parent parent |
--adapter-parent-wwnn parent_wwnn adapter-parent-wwpn parent_wwpn |
--adapter-parent-fabric-wwn parent_fabric_wwn]]
[--build] [[--overwrite] | [--no-overwrite]] [--print-xml]Create and start a pool object name from the raw parameters. If --print-xml is specified, then print the XML of the pool object without creating the pool. Otherwise, the pool has the specified type. When using pool-create-as for a pool of type "disk", the existing partitions found on the --source-dev path will be used to populate the disk pool. Therefore, it is suggested to use pool-define-as and pool-build with the --overwrite in order to properly initialize the disk pool.
[--source-host hostname] provides the source hostname for pools backed by storage from a remote server (pool types netfs, iscsi, rbd, sheepdog, gluster).
[--source-path path] provides the source directory path for pools backed by directories (pool type dir).
[--source-dev path] provides the source path for pools backed by physical devices (pool types fs, logical, disk, iscsi, zfs).
[--source-name name] provides the source name for pools backed by storage from a named element (pool types logical, rbd, sheepdog, gluster).
[--target path] is the path for the mapping of the storage pool into the host file system.
[--source-format format] provides information about the format of the pool (pool types fs, netfs, disk, logical).
[--source-initiator initiator-iqn] provides the initiator iqn for iscsi connection of the pool (pool type iscsi-direct).
[--auth-type authtype --auth-username username [--secret-usage usage | --secret-uuid uuid]] provides the elements required to generate authentication credentials for the storage pool. The authtype is either chap for iscsi type pools or ceph for rbd type pools. Either the secret usage or uuid value may be provided, but not both.
[--source-protocol-ver ver] provides the NFS protocol version number used to contact the server's NFS service via nfs mount option 'nfsvers=n'. It is expect the ver value is an unsigned integer.
[--adapter-name name] defines the scsi_hostN adapter name to be used for the scsi_host adapter type pool.
[--adapter-wwnn wwnn --adapter-wwpn wwpn [--adapter-parent parent | --adapter-parent-wwnn parent_wwnn adapter-parent-wwpn parent_wwpn | --adapter-parent-fabric-wwn parent_fabric_wwn]] defines the wwnn and wwpn to be used for the fc_host adapter type pool. Optionally provide the parent scsi_hostN node device to be used for the vHBA either by parent name, parent_wwnn and parent_wwpn, or parent_fabric_wwn. The parent name could change between reboots if the hardware environment changes, so providing the parent_wwnn and parent_wwpn ensure usage of the same physical HBA even if the scsi_hostN node device changes. Usage of the parent_fabric_wwn allows a bit more flexibility to choose an HBA on the same storage fabric in order to define the pool.
[--build] [[--overwrite] | [--no-overwrite]] perform a pool-build after creation in order to remove the need for a follow-up command to build the pool. The --overwrite and --no-overwrite flags follow the same rules as pool-build. If just --build is provided, then pool-build is called with no flags.
For a "logical" pool only [--name] needs to be provided. The [--source-name] if provided must match the Volume Group name. If not provided, one will be generated using the [--name]. If provided the [--target] is ignored and a target source is generated using the [--source-name] (or as generated from the [--name]).
pool-define
Syntax:
pool-define file [--validate]Define an inactive persistent storage pool or modify an existing persistent one from the XML file. Optionally, the format of the input XML file can be validated against an internal RNG schema with --validate.
pool-define-as
Syntax:
pool-define-as name type
[--source-host hostname] [--source-path path] [--source-dev path]
[*--source-name name*] [*--target path*] [*--source-format format*]
[--source-initiator initiator-iqn]
[*--auth-type authtype* *--auth-username username*
[*--secret-usage usage* | *--secret-uuid uuid*]]
[*--source-protocol-ver ver*]
[[*--adapter-name name*] | [*--adapter-wwnn* *--adapter-wwpn*]
[*--adapter-parent parent*]] [*--print-xml*]Create, but do not start, a pool object name from the raw parameters. If --print-xml is specified, then print the XML of the pool object without defining the pool. Otherwise, the pool has the specified type.
Use the same arguments as pool-create-as, except for the --build, --overwrite, and --no-overwrite options.
pool-destroy
Syntax:
pool-destroy pool-or-uuidDestroy (stop) a given pool object. Libvirt will no longer manage the storage described by the pool object, but the raw data contained in the pool is not changed, and can be later recovered with pool-create.
pool-delete
Syntax:
pool-delete pool-or-uuidDestroy the resources used by a given pool object. This operation is non-recoverable. The pool object will still exist after this command, ready for the creation of new storage volumes.
pool-dumpxml
Syntax:
pool-dumpxml [--inactive] pool-or-uuidReturns the XML information about the pool object. --inactive tells virsh to dump pool configuration that will be used on next start of the pool as opposed to the current pool configuration.
pool-edit
Syntax:
pool-edit pool-or-uuidEdit the XML configuration file for a storage pool.
This is equivalent to:
virsh pool-dumpxml pool > pool.xml
vi pool.xml (or make changes with your other text editor)
virsh pool-define pool.xmlexcept that it does some error checking.
The editor used can be supplied by the $VISUAL or $EDITOR environment variables, and defaults to vi.
pool-info
Syntax:
pool-info [--bytes] pool-or-uuidReturns basic information about the pool object. If --bytes is specified the sizes of basic info are not converted to human friendly units.
pool-list
Syntax:
pool-list [--inactive] [--all]
[--persistent] [--transient]
[--autostart] [--no-autostart]
[[--details] [--uuid]
[--name] [<type>]List pool objects known to libvirt. By default, only active pools are listed; --inactive lists just the inactive pools, and --all lists all pools.
In addition, there are several sets of filtering flags. --persistent is to list the persistent pools, --transient is to list the transient pools. --autostart lists the autostarting pools, --no-autostart lists the pools with autostarting disabled. If --uuid is specified only pool's UUIDs are printed. If --name is specified only pool's names are printed. If both --name and --uuid are specified, pool's UUID and names are printed side by side without any header. Option --details is mutually exclusive with options --uuid and --name.
You may also want to list pools with specified types using type, the pool types must be separated by comma, e.g. --type dir,disk. The valid pool types include 'dir', 'fs', 'netfs', 'logical', 'disk', 'iscsi', 'scsi', 'mpath', 'rbd', 'sheepdog', 'gluster', 'zfs', 'vstorage' and 'iscsi-direct'.
The --details option instructs virsh to additionally display pool persistence and capacity related information where available.
NOTE: When talking to older servers, this command is forced to use a series of API calls with an inherent race, where a pool might not be listed or might appear more than once if it changed state between calls while the list was being collected. Newer servers do not have this problem.
pool-name
Syntax:
pool-name uuidConvert the uuid to a pool name.
pool-refresh
Syntax:
pool-refresh pool-or-uuidRefresh the list of volumes contained in pool.
pool-start
Syntax:
pool-start pool-or-uuid [--build] [[--overwrite] | [--no-overwrite]]Start the storage pool, which is previously defined but inactive.
[--build] [[--overwrite] | [--no-overwrite]] perform a pool-build prior to pool-start to ensure the pool environment is in an expected state rather than needing to run the build command prior to startup. The --overwrite and --no-overwrite flags follow the same rules as pool-build. If just --build is provided, then pool-build is called with no flags.
Note: A storage pool that relies on remote resources such as an "iscsi" or a (v)HBA backed "scsi" pool may need to be refreshed multiple times in order to have all the volumes detected (see pool-refresh). This is because the corresponding volume devices may not be present in the host's filesystem during the initial pool startup or the current refresh attempt. The number of refresh retries is dependent upon the network connection and the time the host takes to export the corresponding devices.
pool-undefine
Syntax:
pool-undefine pool-or-uuidUndefine the configuration for an inactive pool.
pool-uuid
Syntax:
pool-uuid poolReturns the UUID of the named pool.
pool-event
Syntax:
pool-event {[pool] event [--loop] [--timeout seconds] [--timestamp] | --list}Wait for a class of storage pool events to occur, and print appropriate details of events as they happen. The events can optionally be filtered by pool. Using --list as the only argument will provide a list of possible event values known by this client, although the connection might not allow registering for all these events.
By default, this command is one-shot, and returns success once an event occurs; you can send SIGINT (usually via Ctrl-C) to quit immediately. If --timeout is specified, the command gives up waiting for events after seconds have elapsed. With --loop, the command prints all events until a timeout or interrupt key.
When --timestamp is used, a human-readable timestamp will be printed before the event.
VOLUME COMMANDS
vol-create
Syntax:
vol-create pool-or-uuid FILE [--prealloc-metadata]Create a volume from an XML <file>.
pool-or-uuid is the name or UUID of the storage pool to create the volume in.
FILE is the XML <file> with the volume definition. An easy way to create the XML <file> is to use the vol-dumpxml command to obtain the definition of a pre-existing volume.
[--prealloc-metadata] preallocate metadata (for qcow2 images which don't support full allocation). This option creates a sparse image file with metadata, resulting in higher performance compared to images with no preallocation and only slightly higher initial disk space usage.
Example:
virsh vol-dumpxml --pool storagepool1 appvolume1 > newvolume.xml
vi newvolume.xml (or make changes with your other text editor)
virsh vol-create differentstoragepool newvolume.xmlvol-create-from
Syntax:
vol-create-from pool-or-uuid FILE vol-name-or-key-or-path
[--inputpool pool-or-uuid] [--prealloc-metadata] [--reflink]Create a volume, using another volume as input.
pool-or-uuid is the name or UUID of the storage pool to create the volume in.
FILE is the XML <file> with the volume definition.
vol-name-or-key-or-path is the name or key or path of the source volume.
--inputpool pool-or-uuid is the name or uuid of the storage pool the source volume is in.
[--prealloc-metadata] preallocate metadata (for qcow2 images which don't support full allocation). This option creates a sparse image file with metadata, resulting in higher performance compared to images with no preallocation and only slightly higher initial disk space usage.
When --reflink is specified, perform a COW lightweight copy, where the data blocks are copied only when modified. If this is not possible, the copy fails.
vol-create-as
Syntax:
vol-create-as pool-or-uuid name capacity [--allocation size] [--format string]
[--backing-vol vol-name-or-key-or-path]
[--backing-vol-format string] [--prealloc-metadata] [--print-xml]Create a volume from a set of arguments unless --print-xml is specified, in which case just the XML of the volume object is printed out without any actual object creation.
pool-or-uuid is the name or UUID of the storage pool to create the volume in.
name is the name of the new volume. For a disk pool, this must match the partition name as determined from the pool's source device path and the next available partition. For example, a source device path of /dev/sdb and there are no partitions on the disk, then the name must be sdb1 with the next name being sdb2 and so on.
capacity is the size of the volume to be created, as a scaled integer (see NOTES above), defaulting to bytes if there is no suffix.
--allocation size is the initial size to be allocated in the volume, also as a scaled integer defaulting to bytes.
--format string is used in file based storage pools to specify the volume file format to use; raw, bochs, qcow, qcow2, vmdk, qed. Use extended for disk storage pools in order to create an extended partition (other values are validity checked but not preserved when libvirtd is restarted or the pool is refreshed).
--backing-vol vol-name-or-key-or-path is the source backing volume to be used if taking a snapshot of an existing volume.
--backing-vol-format string is the format of the snapshot backing volume; raw, bochs, qcow, qcow2, qed, vmdk, host_device. These are, however, meant for file based storage pools.
[--prealloc-metadata] preallocate metadata (for qcow2 images which don't support full allocation). This option creates a sparse image file with metadata, resulting in higher performance compared to images with no preallocation and only slightly higher initial disk space usage.
vol-clone
Syntax:
vol-clone vol-name-or-key-or-path name
[--pool pool-or-uuid] [--prealloc-metadata] [--reflink]Clone an existing volume within the parent pool. Less powerful, but easier to type, version of vol-create-from.
vol-name-or-key-or-path is the name or key or path of the source volume.
name is the name of the new volume.
--pool pool-or-uuid is the name or UUID of the storage pool that contains the source volume and will contain the new volume. If the source volume name is provided instead of the key or path, then providing the pool is necessary to find the volume to be cloned; otherwise, the first volume found by the key or path will be used.
[--prealloc-metadata] preallocate metadata (for qcow2 images which don't support full allocation). This option creates a sparse image file with metadata, resulting in higher performance compared to images with no preallocation and only slightly higher initial disk space usage.
When --reflink is specified, perform a COW lightweight copy, where the data blocks are copied only when modified. If this is not possible, the copy fails.
vol-delete
Syntax:
vol-delete vol-name-or-key-or-path [--pool pool-or-uuid] [--delete-snapshots]Delete a given volume.
vol-name-or-key-or-path is the volume name or key or path of the volume to delete.
[--pool pool-or-uuid] is the name or UUID of the storage pool the volume is in. If the volume name is provided instead of the key or path, then providing the pool is necessary to find the volume to be deleted; otherwise, the first volume found by the key or path will be used.
The --delete-snapshots flag specifies that any snapshots associated with the storage volume should be deleted as well. Not all storage drivers support this option, presently only rbd.
vol-upload
Syntax:
vol-upload vol-name-or-key-or-path local-file
[--pool pool-or-uuid] [--offset bytes]
[--length bytes] [--sparse]Upload the contents of local-file to a storage volume.
vol-name-or-key-or-path is the name or key or path of the volume where the local-file will be uploaded.
--pool pool-or-uuid is the name or UUID of the storage pool the volume is in. If the volume name is provided instead of the key or path, then providing the pool is necessary to find the volume to be uploaded into; otherwise, the first volume found by the key or path will be used.
--offset is the position in the storage volume at which to start writing the data. The value must be 0 or larger.
--length is an upper bound of the amount of data to be uploaded. A negative value is interpreted as an unsigned long long value to essentially include everything from the offset to the end of the volume.
If --sparse is specified, this command will preserve volume sparseness.
An error will occur if the local-file is greater than the specified length.
See the description for the libvirt virStorageVolUpload API for details regarding possible target volume and pool changes as a result of the pool refresh when the upload is attempted.
vol-download
Syntax:
vol-download vol-name-or-key-or-path local-file
[--pool pool-or-uuid] [--offset bytes] [--length bytes]
[--sparse]Download the contents of a storage volume to local-file.
vol-name-or-key-or-path is the name or key or path of the volume to download into local-file.
--pool pool-or-uuid is the name or UUID of the storage pool the volume is in. If the volume name is provided instead of the key or path, then providing the pool is necessary to find the volume to be uploaded into; otherwise, the first volume found by the key or path will be used.
--offset is the position in the storage volume at which to start reading the data. The value must be 0 or larger.
--length is an upper bound of the amount of data to be downloaded. A negative value is interpreted as an unsigned long long value to essentially include everything from the offset to the end of the volume.
If --sparse is specified, this command will preserve volume sparseness.
vol-wipe
Syntax:
vol-wipe vol-name-or-key-or-path [--pool pool-or-uuid] [--algorithm algorithm]Wipe a volume, ensure data previously on the volume is not accessible to future reads.
vol-name-or-key-or-path is the name or key or path of the volume to wipe. It is possible to choose different wiping algorithms instead of re-writing volume with zeroes.
--pool pool-or-uuid is the name or UUID of the storage pool the volume is in. If the volume name is provided instead of the key or path, then providing the pool is necessary to find the volume to be wiped; otherwise, the first volume found by the key or path will be used.
Use the --algorithm switch choosing from the list of the following algorithms in order to define which algorithm to use for the wipe.
Supported algorithms
- zero - 1-pass all zeroes
- nnsa - 4-pass NNSA Policy Letter NAP-14.1-C (XVI-8) for sanitizing removable and non-removable hard disks: random x2, 0x00, verify.
- dod - 4-pass DoD 5220.22-M section 8-306 procedure for sanitizing removable and non-removable rigid disks: random, 0x00, 0xff, verify.
- bsi - 9-pass method recommended by the German Center of Security in Information Technologies (https://www.bsi.bund.de): 0xff, 0xfe, 0xfd, 0xfb, 0xf7, 0xef, 0xdf, 0xbf, 0x7f.
- gutmann - The canonical 35-pass sequence described in Gutmann's paper.
- schneier - 7-pass method described by Bruce Schneier in "Applied Cryptography" (1996): 0x00, 0xff, random x5.
- pfitzner7 - Roy Pfitzner's 7-random-pass method: random x7.
- pfitzner33 - Roy Pfitzner's 33-random-pass method: random x33.
- random - 1-pass pattern: random.
- trim - 1-pass trimming the volume using TRIM or DISCARD
Note: The scrub binary will be used to handle the 'nnsa', 'dod', 'bsi', 'gutmann', 'schneier', 'pfitzner7' and 'pfitzner33' algorithms. The availability of the algorithms may be limited by the version of the scrub binary installed on the host. The 'zero' algorithm will write zeroes to the entire volume. For some volumes, such as sparse or rbd volumes, this may result in completely filling the volume with zeroes making it appear to be completely full. As an alternative, the 'trim' algorithm does not overwrite all the data in a volume, rather it expects the storage driver to be able to discard all bytes in a volume. It is up to the storage driver to handle how the discarding occurs. Not all storage drivers or volume types can support 'trim'.
vol-dumpxml
Syntax:
vol-dumpxml vol-name-or-key-or-path [--pool pool-or-uuid]Output the volume information as an XML dump to stdout.
vol-name-or-key-or-path is the name or key or path of the volume to output the XML.
--pool pool-or-uuid is the name or UUID of the storage pool the volume is in. If the volume name is provided instead of the key or path, then providing the pool is necessary to find the volume to be uploaded into; otherwise, the first volume found by the key or path will be used.
vol-info
Syntax:
vol-info vol-name-or-key-or-path [--pool pool-or-uuid] [--bytes] [--physical]Returns basic information about the given storage volume.
vol-name-or-key-or-path is the name or key or path of the volume to return information for.
--pool pool-or-uuid is the name or UUID of the storage pool the volume is in. If the volume name is provided instead of the key or path, then providing the pool is necessary to find the volume to be uploaded into; otherwise, the first volume found by the key or path will be used.
If --bytes is specified the sizes are not converted to human friendly units.
If --physical is specified, then the host physical size is returned and displayed instead of the allocation value. The physical value for some file types, such as qcow2 may have a different (larger) physical value than is shown for allocation. Additionally sparse files will have different physical and allocation values.
vol-list
Syntax:
vol-list [--pool pool-or-uuid] [--details]Return the list of volumes in the given storage pool.
--pool pool-or-uuid is the name or UUID of the storage pool.
The --details option instructs virsh to additionally display volume type and capacity related information where available.
vol-pool
Syntax:
vol-pool vol-key-or-path [--uuid]Return the pool name or UUID for a given volume. By default, the pool name is returned.
vol-key-or-path is the key or path of the volume to return the pool information.
If the --uuid option is given, the pool UUID is returned instead.
vol-path
Syntax:
vol-path vol-name-or-key [--pool pool-or-uuid]Return the path for a given volume.
vol-name-or-key is the name or key of the volume to return the path.
--pool pool-or-uuid is the name or UUID of the storage pool the volume is in. If the volume name is provided instead of the key, then providing the pool is necessary to find the volume to be uploaded into; otherwise, the first volume found by the key will be used.
vol-name
Syntax:
vol-name vol-key-or-pathReturn the name for a given volume.
vol-key-or-path is the key or path of the volume to return the name.
vol-key
Syntax:
vol-key vol-name-or-path [--pool pool-or-uuid]Return the volume key for a given volume.
vol-name-or-path is the name or path of the volume to return the volume key.
--pool pool-or-uuid is the name or UUID of the storage pool the volume is in. If the volume name is provided instead of the path, then providing the pool is necessary to find the volume to be uploaded into; otherwise, the first volume found by the path will be used.
vol-resize
Syntax:
vol-resize vol-name-or-path capacity [--pool pool-or-uuid] [--allocate] [--delta] [--shrink]Resize the capacity of the given volume, in bytes.
vol-name-or-key-or-path is the name or key or path of the volume to resize.
capacity is a scaled integer (see NOTES above) for the volume, which defaults to bytes if there is no suffix.
--pool pool-or-uuid is the name or UUID of the storage pool the volume is in. If the volume name is provided instead of the key or path, then providing the pool is necessary to find the volume to be uploaded into; otherwise, the first volume found by the key or path will be used.
The new capacity might be sparse unless --allocate is specified.
Normally, capacity is the new size, but if --delta is present, then it is added to the existing size.
Attempts to shrink the volume will fail unless --shrink is present. The capacity cannot be negative unless --shrink is provided, but a negative sign is not necessary.
This command is only safe for storage volumes not in use by an active guest; see also blockresize for live resizing.
SECRET COMMANDS
The following commands manipulate "secrets" (e.g. passwords, passphrases and encryption keys). Libvirt can store secrets independently from their use, and other objects (e.g. volumes or domains) can refer to the secrets for encryption or possibly other uses. Secrets are identified using a UUID. See https://libvirt.org/formatsecret.html for documentation of the XML format used to represent properties of secrets.
secret-define
Syntax:
secret-define file [--validate]Create a secret with the properties specified in file, with no associated secret value. If file does not specify a UUID, choose one automatically. If file specifies a UUID of an existing secret, replace its properties by properties defined in file, without affecting the secret value.
Optionally, the format of the input XML file can be validated against an internal RNG schema with --validate.
secret-dumpxml
Syntax:
secret-dumpxml secretOutput properties of secret (specified by its UUID) as an XML dump to stdout.
secret-event
Syntax:
secret-event {[secret] event [--loop] [--timeout seconds] [--timestamp] | --list}Wait for a class of secret events to occur, and print appropriate details of events as they happen. The events can optionally be filtered by secret. Using --list as the only argument will provide a list of possible event values known by this client, although the connection might not allow registering for all these events.
By default, this command is one-shot, and returns success once an event occurs; you can send SIGINT (usually via Ctrl-C) to quit immediately. If --timeout is specified, the command gives up waiting for events after seconds have elapsed. With --loop, the command prints all events until a timeout or interrupt key.
When --timestamp is used, a human-readable timestamp will be printed before the event.
secret-set-value
Syntax:
secret-set-value secret (--file filename [--plain] | --interactive | base64)Set the value associated with secret (specified by its UUID) to the value Base64-encoded value base64 or Base-64-encoded contents of file named filename. Using the --plain flag is together with --file allows one to use the file contents directly as the secret value.
If --interactive flag is used the secret value is read as a password from the terminal.
Note that --file, --interactive and base64 options are mutually exclusive.
Passing secrets via the base64 option on command line is INSECURE and deprecated. Use the --file option instead.
secret-get-value
Syntax:
secret-get-value [--plain] secretOutput the value associated with secret (specified by its UUID) to stdout, encoded using Base64.
If the --plain flag is used the value is not base64 encoded, but rather printed raw. Note that unless virsh is started in quiet mode (virsh -q) it prints a newline at the end of the command. This newline is not part of the secret.
secret-undefine
Syntax:
secret-undefine secretDelete a secret (specified by its UUID), including the associated value, if any.
secret-list
Syntax:
secret-list [--ephemeral] [--no-ephemeral]
[--private] [--no-private]Returns the list of secrets. You may also want to filter the returned secrets by --ephemeral to list the ephemeral ones, --no-ephemeral to list the non-ephemeral ones, --private to list the private ones, and --no-private to list the non-private ones.
SNAPSHOT COMMANDS
The following commands manipulate domain snapshots. Snapshots take the disk, memory, and device state of a domain at a point-of-time, and save it for future use. They have many uses, from saving a "clean" copy of an OS image to saving a domain's state before a potentially destructive operation. Snapshots are identified with a unique name. See https://libvirt.org/formatsnapshot.html for documentation of the XML format used to represent properties of snapshots.
snapshot-create
Syntax:
snapshot-create domain [xmlfile] {[--redefine [--current]] |
[--no-metadata] [--halt] [--disk-only] [--reuse-external]
[--quiesce] [--atomic] [--live]} [--validate]Create a snapshot for domain domain with the properties specified in xmlfile. Optionally, the --validate option can be passed to validate the format of the input XML file against an internal RNG schema (identical to using the virt-xml-validate(1) tool). Normally, the only properties settable for a domain snapshot are the <name> and <description> elements, as well as <disks> if --disk-only is given; the rest of the fields are ignored, and automatically filled in by libvirt. If xmlfile is completely omitted, then libvirt will choose a value for all fields. The new snapshot will become current, as listed by snapshot-current.
If --halt is specified, the domain will be left in an inactive state after the snapshot is created.
If --disk-only is specified, the snapshot will only include disk content rather than the usual full system snapshot with vm state. Disk snapshots are captured faster than full system snapshots, but reverting to a disk snapshot may require fsck or journal replays, since it is like the disk state at the point when the power cord is abruptly pulled; and mixing --halt and --disk-only loses any data that was not flushed to disk at the time.
If --redefine is specified, then all XML elements produced by snapshot-dumpxml are valid; this can be used to migrate snapshot hierarchy from one machine to another, to recreate hierarchy for the case of a transient domain that goes away and is later recreated with the same name and UUID, or to make slight alterations in the snapshot metadata (such as host-specific aspects of the domain XML embedded in the snapshot). When this flag is supplied, the xmlfile argument is mandatory, and the domain's current snapshot will not be altered unless the --current flag is also given.
If --no-metadata is specified, then the snapshot data is created, but any metadata is immediately discarded (that is, libvirt does not treat the snapshot as current, and cannot revert to the snapshot unless --redefine is later used to teach libvirt about the metadata again).
If --reuse-external is specified, and the snapshot XML requests an external snapshot with a destination of an existing file, then the destination must exist and be pre-created with correct format and metadata. The file is then reused; otherwise, a snapshot is refused to avoid losing contents of the existing files.
If --quiesce is specified, libvirt will try to use guest agent to freeze and unfreeze domain's mounted file systems. However, if domain has no guest agent, snapshot creation will fail. Currently, this requires --disk-only to be passed as well.
If --atomic is specified, libvirt will guarantee that the snapshot either succeeds, or fails with no changes; not all hypervisors support this. If this flag is not specified, then some hypervisors may fail after partially performing the action, and dumpxml must be used to see whether any partial changes occurred.
If --live is specified, libvirt takes the snapshot while the guest is running. Both disk snapshot and domain memory snapshot are taken. This increases the size of the memory image of the external snapshot. This is currently supported only for full system external snapshots.
Existence of snapshot metadata will prevent attempts to undefine a persistent guest. However, for transient domains, snapshot metadata is silently lost when the domain quits running (whether by command such as destroy or by internal guest action).
For now, it is not possible to create snapshots in a domain that has checkpoints, although this restriction will be lifted in a future release.
snapshot-create-as
Syntax:
snapshot-create-as domain {[--print-xml] [--no-metadata]
[--halt] [--reuse-external]} [name]
[description] [--disk-only [--quiesce]] [--atomic] [--validate]
[[--live] [--memspec memspec]] [--diskspec] diskspec]...Create a snapshot for domain domain with the given <name> and <description>; if either value is omitted, libvirt will choose a value. If --print-xml is specified, then XML appropriate for snapshot-create is output, rather than actually creating a snapshot. Otherwise, if --halt is specified, the domain will be left in an inactive state after the snapshot is created, and if --disk-only is specified, the snapshot will not include vm state.
The --memspec option can be used to control whether a full system snapshot is internal or external. The --memspec flag is mandatory, followed by a memspec of the form [file=]name[,snapshot=type], where type can be no, internal, or external. To include a literal comma in file=name, escape it with a second comma. --memspec cannot be used together with --disk-only.
The --diskspec option can be used to control how --disk-only and external full system snapshots create external files. This option can occur multiple times, according to the number of <disk> elements in the domain xml. Each <diskspec> is in the form disk[,snapshot=type][,driver=type][,stype=type][,file=name]. A diskspec must be provided for disks backed by block devices as libvirt doesn't auto-generate file names for those. The optional stype parameter allows one to control the type of the source file. Supported values are 'file' (default) and 'block'. To exclude a disk from an external snapshot use --diskspec disk,snapshot=no.
To include a literal comma in disk or in file=name, escape it with a second comma. A literal --diskspec must precede each diskspec unless all three of domain, name, and description are also present. For example, a diskspec of "vda,snapshot=external,file=/path/to,,new" results in the following XML:
<disk name='vda' snapshot='external'>
<source file='/path/to,new'/>
</disk>If --reuse-external is specified, and the domain XML or diskspec option requests an external snapshot with a destination of an existing file, then the destination must exist and be pre-created with correct format and metadata. The file is then reused; otherwise, a snapshot is refused to avoid losing contents of the existing files.
If --quiesce is specified, libvirt will try to use guest agent to freeze and unfreeze domain's mounted file systems. However, if domain has no guest agent, snapshot creation will fail. Currently, this requires --disk-only to be passed as well.
If --no-metadata is specified, then the snapshot data is created, but any metadata is immediately discarded (that is, libvirt does not treat the snapshot as current, and cannot revert to the snapshot unless snapshot-create is later used to teach libvirt about the metadata again).
If --atomic is specified, libvirt will guarantee that the snapshot either succeeds, or fails with no changes; not all hypervisors support this. If this flag is not specified, then some hypervisors may fail after partially performing the action, and dumpxml must be used to see whether any partial changes occurred.
If --live is specified, libvirt takes the snapshot while the guest is running. This increases the size of the memory image of the external snapshot. This is currently supported only for external full system snapshots.
For now, it is not possible to create snapshots in a domain that has checkpoints, although this restriction will be lifted in a future release.
Optionally, the --validate option can be passed to validate XML document which is internally generated by this command against the internal RNG schema.
snapshot-current
Syntax:
snapshot-current domain {[--name] | [--security-info] | [snapshotname]}Without snapshotname, this will output the snapshot XML for the domain's current snapshot (if any). If --name is specified, just the current snapshot name instead of the full xml. Otherwise, using --security-info will also include security sensitive information in the XML.
With snapshotname, this is a request to make the existing named snapshot become the current snapshot, without reverting the domain.
snapshot-edit
Syntax:
snapshot-edit domain [snapshotname] [--current] {[--rename] | [--clone]}Edit the XML configuration file for snapshotname of a domain. If both snapshotname and --current are specified, also force the edited snapshot to become the current snapshot. If snapshotname is omitted, then --current must be supplied, to edit the current snapshot.
This is equivalent to:
virsh snapshot-dumpxml dom name > snapshot.xml
vi snapshot.xml (or make changes with your other text editor)
virsh snapshot-create dom snapshot.xml --redefine [--current]except that it does some error checking.
The editor used can be supplied by the $VISUAL or $EDITOR environment variables, and defaults to vi.
If --rename is specified, then the edits can change the snapshot name. If --clone is specified, then changing the snapshot name will create a clone of the snapshot metadata. If neither is specified, then the edits must not change the snapshot name. Note that changing a snapshot name must be done with care, since the contents of some snapshots, such as internal snapshots within a single qcow2 file, are accessible only from the original name.
snapshot-info
Syntax:
snapshot-info domain {snapshot | --current}Output basic information about a named <snapshot>, or the current snapshot with --current.
snapshot-list
Syntax:
snapshot-list domain [--metadata] [--no-metadata]
[{--parent | --roots | [{--tree | --name}]}] [--topological]
[{[--from] snapshot | --current} [--descendants]]
[--leaves] [--no-leaves] [--inactive] [--active]
[--disk-only] [--internal] [--external]List all of the available snapshots for the given domain, defaulting to show columns for the snapshot name, creation time, and domain state.
Normally, table form output is sorted by snapshot name; using --topological instead sorts so that no child is listed before its ancestors (although there may be more than one possible ordering with this property).
If --parent is specified, add a column to the output table giving the name of the parent of each snapshot. If --roots is specified, the list will be filtered to just snapshots that have no parents. If --tree is specified, the output will be in a tree format, listing just snapshot names. These three options are mutually exclusive. If --name is specified only the snapshot name is printed. This option is mutually exclusive with --tree.
If --from is provided, filter the list to snapshots which are children of the given snapshot; or if --current is provided, start at the current snapshot. When used in isolation or with --parent, the list is limited to direct children unless --descendants is also present. When used with --tree, the use of --descendants is implied. This option is not compatible with --roots. Note that the starting point of --from or --current is not included in the list unless the --tree option is also present.
If --leaves is specified, the list will be filtered to just snapshots that have no children. Likewise, if --no-leaves is specified, the list will be filtered to just snapshots with children. (Note that omitting both options does no filtering, while providing both options will either produce the same list or error out depending on whether the server recognizes the flags). Filtering options are not compatible with --tree.
If --metadata is specified, the list will be filtered to just snapshots that involve libvirt metadata, and thus would prevent undefine of a persistent guest, or be lost on destroy of a transient domain. Likewise, if --no-metadata is specified, the list will be filtered to just snapshots that exist without the need for libvirt metadata.
If --inactive is specified, the list will be filtered to snapshots that were taken when the domain was shut off. If --active is specified, the list will be filtered to snapshots that were taken when the domain was running, and where the snapshot includes the memory state to revert to that running state. If --disk-only is specified, the list will be filtered to snapshots that were taken when the domain was running, but where the snapshot includes only disk state.
If --internal is specified, the list will be filtered to snapshots that use internal storage of existing disk images. If --external is specified, the list will be filtered to snapshots that use external files for disk images or memory state.
snapshot-dumpxml
Syntax:
snapshot-dumpxml domain snapshot [--security-info]Output the snapshot XML for the domain's snapshot named snapshot. Using --security-info will also include security sensitive information. Use snapshot-current to easily access the XML of the current snapshot.
snapshot-parent
Syntax:
snapshot-parent domain {snapshot | --current}Output the name of the parent snapshot, if any, for the given snapshot, or for the current snapshot with --current.
snapshot-revert
Syntax:
snapshot-revert domain {snapshot | --current} [{--running | --paused}]
[--force] [--reset-nvram]Revert the given domain to the snapshot specified by snapshot, or to the current snapshot with --current. Be aware that this is a destructive action; any changes in the domain since the last snapshot was taken will be lost. Also note that the state of the domain after snapshot-revert is complete will be the state of the domain at the time the original snapshot was taken.
Normally, reverting to a snapshot leaves the domain in the state it was at the time the snapshot was created, except that a disk snapshot with no vm state leaves the domain in an inactive state. Passing either the --running or --paused flag will perform additional state changes (such as booting an inactive domain, or pausing a running domain). Since transient domains cannot be inactive, it is required to use one of these flags when reverting to a disk snapshot of a transient domain.
Since libvirt 7.10.0 the VM process is always restarted so the following paragraph is no longer valid. If the snapshot metadata lacks the full VM XML it's no longer possible to revert to such snapshot.
There are a number of cases where a snapshot revert involves extra risk, which requires the use of --force to proceed:
- One is the case of a snapshot that lacks full domain information for reverting configuration (such as snapshots created prior to libvirt 0.9.5); since libvirt cannot prove that the current configuration matches what was in use at the time of the snapshot, supplying --force assures libvirt that the snapshot is compatible with the current configuration (and if it is not, the domain will likely fail to run).
- Another is the case of reverting from a running domain to an active state where a new hypervisor has to be created rather than reusing the existing hypervisor, because it implies drawbacks such as breaking any existing VNC or Spice connections; this condition happens with an active snapshot that uses a provably incompatible configuration, as well as with an inactive snapshot that is combined with the --start or --pause flag.
- Also, libvirt will refuse to restore snapshots of inactive QEMU domains while there is managed saved state. This is because those snapshots do not contain memory state and will therefore not replace the existing memory state. This ends up switching a disk underneath a running system and will likely cause extensive filesystem corruption or crashes due to swap content mismatches when run.
If --reset-nvram is specified, any existing NVRAM file will be deleted and re-initialized from its pristine template.
snapshot-delete
Syntax:
snapshot-delete domain {snapshot | --current}
[--metadata] [{--children | --children-only}]Delete the snapshot for the domain named snapshot, or the current snapshot with --current. If this snapshot has child snapshots, changes from this snapshot will be merged into the children. If --children is passed, then delete this snapshot and any children of this snapshot. If --children-only is passed, then delete any children of this snapshot, but leave this snapshot intact. These two flags are mutually exclusive.
If --metadata is specified, then only delete the snapshot metadata maintained by libvirt, while leaving the snapshot contents intact for access by external tools; otherwise deleting a snapshot also removes the data contents from that point in time.
CHECKPOINT COMMANDS
The following commands manipulate domain checkpoints. Checkpoints serve as a point in time to identify which portions of a guest's disks have changed after that time, making it possible to perform incremental and differential backups. Checkpoints are identified with a unique name. See https://libvirt.org/formatcheckpoint.html for documentation of the XML format used to represent properties of checkpoints.
checkpoint-create
Syntax:
checkpoint-create domain [xmlfile] { --redefine [--redefine-validate] | [--quiesce]}Create a checkpoint for domain domain with the properties specified in xmlfile describing a <domaincheckpoint> top-level element. The format of the input XML file will be validated against an internal RNG schema (identical to using the virt-xml-validate(1) tool). If xmlfile is completely omitted, then libvirt will create a checkpoint with a name based on the current time.
If --redefine is specified, then all XML elements produced by checkpoint-dumpxml are valid; this can be used to migrate checkpoint hierarchy from one machine to another, to recreate hierarchy for the case of a transient domain that goes away and is later recreated with the same name and UUID, or to make slight alterations in the checkpoint metadata (such as host-specific aspects of the domain XML embedded in the checkpoint). When this flag is supplied, the xmlfile argument is mandatory.
If --redefine-validate is specified along with --redefine the hypervisor performs validation of metadata associated with the checkpoint stored in places besides the checkpoint XML. Note that some hypervisors may require that the domain is running to perform validation.
If --quiesce is specified, libvirt will try to use guest agent to freeze and unfreeze domain's mounted file systems. However, if domain has no guest agent, checkpoint creation will fail.
Existence of checkpoint metadata will prevent attempts to undefine a persistent guest. However, for transient domains, checkpoint metadata is silently lost when the domain quits running (whether by command such as destroy or by internal guest action).
For now, it is not possible to create checkpoints in a domain that has snapshots, although this restriction will be lifted in a future release.
checkpoint-create-as
Syntax:
checkpoint-create-as domain [--print-xml] [name]
[description] [--quiesce] [--diskspec] diskspec]...Create a checkpoint for domain domain with the given <name> and <description>; if either value is omitted, libvirt will choose a value. If --print-xml is specified, then XML appropriate for checkpoint-create is output, rather than actually creating a checkpoint.
The --diskspec option can be used to control which guest disks participate in the checkpoint. This option can occur multiple times, according to the number of <disk> elements in the domain xml. Each <diskspec> is in the form disk[,checkpoint=type][,bitmap=name]. A literal --diskspec must precede each diskspec unless all three of domain, name, and description are also present. For example, a diskspec of "vda,checkpoint=bitmap,bitmap=map1" results in the following XML:
<disk name='vda' checkpoint='bitmap' bitmap='map1'/>If --quiesce is specified, libvirt will try to use guest agent to freeze and unfreeze domain's mounted file systems. However, if domain has no guest agent, checkpoint creation will fail.
For now, it is not possible to create checkpoints in a domain that has snapshots, although this restriction will be lifted in a future release.
checkpoint-edit
Syntax:
checkpoint-edit domain checkpointnameEdit the XML configuration file for checkpointname of a domain.
This is equivalent to:
virsh checkpoint-dumpxml dom name > checkpoint.xml
vi checkpoint.xml (or make changes with your other text editor)
virsh checkpoint-create dom checkpoint.xml --redefineexcept that it does some error checking, including that the edits should not attempt to change the checkpoint name.
The editor used can be supplied by the $VISUAL or $EDITOR environment variables, and defaults to vi.
checkpoint-info
Syntax:
checkpoint-info domain checkpointOutput basic information about a named <checkpoint>.
checkpoint-list
Syntax:
checkpoint-list domain [{--parent | --roots |
[{--tree | --name}]}] [--topological]
[[--from] checkpoint | [--descendants]]
[--leaves] [--no-leaves]List all of the available checkpoints for the given domain, defaulting to show columns for the checkpoint name and creation time.
Normally, table form output is sorted by checkpoint name; using --topological instead sorts so that no child is listed before its ancestors (although there may be more than one possible ordering with this property).
If --parent is specified, add a column to the output table giving the name of the parent of each checkpoint. If --roots is specified, the list will be filtered to just checkpoints that have no parents. If --tree is specified, the output will be in a tree format, listing just checkpoint names. These three options are mutually exclusive. If --name is specified only the checkpoint name is printed. This option is mutually exclusive with --tree.
If --from is provided, filter the list to checkpoints which are children of the given checkpoint. When used in isolation or with --parent, the list is limited to direct children unless --descendants is also present. When used with --tree, the use of --descendants is implied. This option is not compatible with --roots. Note that the starting point of --from is not included in the list unless the --tree option is also present.
If --leaves is specified, the list will be filtered to just checkpoints that have no children. Likewise, if --no-leaves is specified, the list will be filtered to just checkpoints with children. (Note that omitting both options does no filtering, while providing both options will either produce the same list or error out depending on whether the server recognizes the flags). Filtering options are not compatible with --tree.
checkpoint-dumpxml
Syntax:
checkpoint-dumpxml domain checkpoint [--security-info] [--no-domain] [--size]Output the checkpoint XML for the domain's checkpoint named checkpoint. Using --security-info will also include security sensitive information.
Using --size will add XML indicating the current size in bytes of guest data that has changed since the checkpoint was created (although remember that guest activity between a size check and actually creating a backup can result in the backup needing slightly more space). Note that some hypervisors may require that domain is running when --size is used.
Using --no-domain will omit the <domain> element from the output for a more compact view.
checkpoint-parent
Syntax:
checkpoint-parent domain checkpointOutput the name of the parent checkpoint, if any, for the given checkpoint.
checkpoint-delete
Syntax:
checkpoint-delete domain checkpoint
[--metadata] [{--children | --children-only}]Delete the checkpoint for the domain named checkpoint. The record of which portions of the disk changed since the checkpoint are merged into the parent checkpoint (if any). If --children is passed, then delete this checkpoint and any children of this checkpoint. If --children-only is passed, then delete any children of this checkpoint, but leave this checkpoint intact. These two flags are mutually exclusive.
If --metadata is specified, then only delete the checkpoint metadata maintained by libvirt, while leaving the checkpoint contents intact for access by external tools; otherwise deleting a checkpoint also removes the ability to perform an incremental backup from that point in time.
NWFILTER COMMANDS
The following commands manipulate network filters. Network filters allow filtering of the network traffic coming from and going to virtual machines. Individual network traffic filters are written in XML and may contain references to other network filters, describe traffic filtering rules, or contain both. Network filters are referenced by virtual machines from within their interface description. A network filter may be referenced by multiple virtual machines' interfaces.
nwfilter-define
Syntax:
nwfilter-define xmlfile [--validate]Make a new network filter known to libvirt. If a network filter with the same name already exists, it will be replaced with the new XML. Any running virtual machine referencing this network filter will have its network traffic rules adapted. If for any reason the network traffic filtering rules cannot be instantiated by any of the running virtual machines, then the new XML will be rejected.
Optionally, the format of the input XML file can be validated against an internal RNG schema with --validate.
nwfilter-undefine
Syntax:
nwfilter-undefine nwfilter-nameDelete a network filter. The deletion will fail if any running virtual machine is currently using this network filter.
nwfilter-list
Syntax:
nwfilter-listList all of the available network filters.
nwfilter-dumpxml
Syntax:
nwfilter-dumpxml nwfilter-nameOutput the network filter XML.
nwfilter-edit
Syntax:
nwfilter-edit nwfilter-nameEdit the XML of a network filter.
This is equivalent to:
virsh nwfilter-dumpxml myfilter > myfilter.xml
vi myfilter.xml (or make changes with your other text editor)
virsh nwfilter-define myfilter.xmlexcept that it does some error checking. The new network filter may be rejected due to the same reason as mentioned in nwfilter-define.
The editor used can be supplied by the $VISUAL or $EDITOR environment variables, and defaults to vi.
NWFILTER BINDING COMMANDS
The following commands manipulate network filter bindings. Network filter bindings track the association between a network port and a network filter. Generally the bindings are managed automatically by the hypervisor drivers when adding/removing NICs on a guest.
If an admin is creating/deleting TAP devices for non-guest usage, however, the network filter binding commands provide a way to make use of the network filters directly.
nwfilter-binding-create
Syntax:
nwfilter-binding-create xmlfile [--validate]Associate a network port with a network filter. The network filter backend will immediately attempt to instantiate the filter rules on the port. This command may be used to associate a filter with a currently running guest that does not have a filter defined for a specific network port. Since the bindings are generally automatically managed by the hypervisor, using this command to define a filter for a network port and then starting the guest afterwards may prevent the guest from starting if it attempts to use the network port and finds a filter already defined.
Optionally, the format of the input XML file can be validated against an internal RNG schema with --validate.
nwfilter-binding-delete
Syntax:
nwfilter-binding-delete port-nameDisassociate a network port from a network filter. The network filter backend will immediately tear down the filter rules that exist on the port. This command may be used to remove the network port binding for a filter currently in use for the guest while the guest is running without needing to restart the guest. Restoring the network port binding filter for the running guest would be accomplished by using nwfilter-binding-create.
nwfilter-binding-list
Syntax:
nwfilter-binding-listList all of the network ports which have filters associated with them.
nwfilter-binding-dumpxml
Syntax:
nwfilter-binding-dumpxml port-nameOutput the network filter binding XML for the network device called port-name.
HYPERVISOR-SPECIFIC COMMANDS
NOTE: Use of the following commands is strongly discouraged. They can cause libvirt to become confused and do the wrong thing on subsequent operations. Once you have used these commands, please do not report problems to the libvirt developers; the reports will be ignored. If you find that these commands are the only way to accomplish something, then it is better to request that the feature be added as a first-class citizen in the regular libvirt library.
qemu-attach
Syntax:
qemu-attach pidAttach an externally launched QEMU process to the libvirt QEMU driver. The QEMU process must have been created with a monitor connection using the UNIX driver. Ideally the process will also have had the '-name' argument specified.
$ qemu-kvm -cdrom ~/demo.iso \
-monitor unix:/tmp/demo,server,nowait \
-name foo \
-uuid cece4f9f-dff0-575d-0e8e-01fe380f12ea &
$ QEMUPID=$!
$ virsh qemu-attach $QEMUPIDNot all functions of libvirt are expected to work reliably after attaching to an externally launched QEMU process. There may be issues with the guest ABI changing upon migration and device hotplug or hotunplug may not work. The attached environment should be considered primarily read-only.
qemu-monitor-command
Syntax:
qemu-monitor-command domain { [--hmp] | [--pretty] [--return-value] } command...Send an arbitrary monitor command command to domain domain through the QEMU monitor. The results of the command will be printed on stdout.
If more than one argument is provided for command, they are concatenated with a space in between before passing the single command to the monitor.
Note that libvirt uses the QMP to talk to qemu so command must be valid JSON in QMP format to work properly. If command is not a JSON object libvirt tries to wrap it as a JSON object to provide convenient interface such as the groups of commands with identical handling:
# simple command
$ virsh qemu-monitor-command VM commandname
$ virsh qemu-monitor-command VM '{"execute":"commandname"}'
# with arguments
$ virsh qemu-monitor-command VM commandname '"arg1":123' '"arg2":"test"'
$ virsh qemu-monitor-command VM commandname '{"arg1":123,"arg2":"test"}'
$ virsh qemu-monitor-command VM '{"execute":"commandname", "arguments":{"arg1":123,"arg2":"test"}}'If --pretty is given the QMP reply is pretty-printed.
If --return-value is given the 'return' key of the QMP response object is extracted rather than passing through the full reply from QEMU.
If --hmp is passed, the command is considered to be a human monitor command and libvirt will automatically convert it into QMP and convert the result back.
qemu-agent-command
Syntax:
qemu-agent-command domain [--timeout seconds | --async | --block] command...Send an arbitrary guest agent command command to domain domain through QEMU agent. --timeout, --async and --block options are exclusive. --timeout requires timeout seconds seconds and it must be positive. When --aysnc is given, the command waits for timeout whether success or failed. And when --block is given, the command waits forever with blocking timeout.
qemu-monitor-event
Syntax:
qemu-monitor-event [domain] [--event event-name]
[--loop] [--timeout seconds] [--pretty] [--regex] [--no-case]
[--timestamp]Wait for arbitrary QEMU monitor events to occur, and print out the details of events as they happen. The events can optionally be filtered by domain or event-name. The 'query-events' QMP command can be used via qemu-monitor-command to learn what events are supported. If --regex is used, event-name is a basic regular expression instead of a literal string. If --no-case is used, event-name will match case-insensitively.
By default, this command is one-shot, and returns success once an event occurs; you can send SIGINT (usually via Ctrl-C) to quit immediately. If --timeout is specified, the command gives up waiting for events after seconds have elapsed. With --loop, the command prints all events until a timeout or interrupt key. If --pretty is specified, any JSON event details are pretty-printed for better legibility.
When --timestamp is used, a human-readable timestamp will be printed before the event, and the timing information provided by QEMU will be omitted.
lxc-enter-namespace
Syntax:
lxc-enter-namespace domain [--noseclabel] --
/path/to/binary [arg1, [arg2, ...]]Enter the namespace of domain and execute the command /path/to/binary passing the requested args. The binary path is relative to the container root filesystem, not the host root filesystem. The binary will inherit the environment variables / console visible to virsh. The command will be run with the same sVirt context and cgroups placement as processes within the container. This command only works when connected to the LXC hypervisor driver. This command succeeds only if /path/to/binary has 0 exit status.
By default the new process will run with the security label of the new parent container. Use the --noseclabel option to instead have the process keep the same security label as virsh.
ENVIRONMENT
The following environment variables can be set to alter the behaviour of virsh
VIRSH_DEBUG=<0 to 4>
Turn on verbose debugging of virsh commands. Valid levels are
VIRSH_DEBUG=0
DEBUG - Messages at ALL levels get logged
VIRSH_DEBUG=1
INFO - Logs messages at levels INFO, NOTICE, WARNING and ERROR
VIRSH_DEBUG=2
NOTICE - Logs messages at levels NOTICE, WARNING and ERROR
VIRSH_DEBUG=3
WARNING - Logs messages at levels WARNING and ERROR
VIRSH_DEBUG=4
ERROR - Messages at only ERROR level gets logged.
VIRSH_LOG_FILE=
LOGFILEThe file to log virsh debug messages.
VIRSH_DEFAULT_CONNECT_URI
The hypervisor to connect to by default. Set this to a URI, in the same format as accepted by the
connectoption. This environment variable is deprecated in favour of the globalLIBVIRT_DEFAULT_URIvariable which serves the same purpose.LIBVIRT_DEFAULT_URI
The hypervisor to connect to by default. Set this to a URI, in the same format as accepted by the
connectoption. This overrides the default URI set in any client config file and prevents libvirt from probing for drivers.VISUAL
The editor to use by the
editand related options.EDITOR
The editor to use by the
editand related options, ifVISUALis not set.VIRSH_HISTSIZE
The number of commands to remember in the command history. The default value is 500.
LIBVIRT_DEBUG=LEVEL
Turn on verbose debugging of all libvirt API calls. Valid levels are
LIBVIRT_DEBUG=1
Messages at level DEBUG or above
LIBVIRT_DEBUG=2
Messages at level INFO or above
LIBVIRT_DEBUG=3
Messages at level WARNING or above
LIBVIRT_DEBUG=4
Messages at level ERROR
For further information about debugging options consult https://libvirt.org/logging.html
BUGS
Please report all bugs you discover. This should be done via either:
the mailing list
the bug tracker
Alternatively, you may report bugs to your software distributor / vendor.
AUTHORS
Please refer to the AUTHORS file distributed with libvirt.
COPYRIGHT
Copyright (C) 2005, 2007-2015 Red Hat, Inc., and the authors listed in the libvirt AUTHORS file.
LICENSE
virsh is distributed under the terms of the GNU LGPL v2+. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE
SEE ALSO
virt-install(1), virt-xml-validate(1), virt-top(1), virt-df(1), https://libvirt.org/