libvirt/docs/virsh.pod

=head1 NAME

virsh - management user interface

=head1 SYNOPSIS

virsh <subcommand> [args]

=head1 DESCRIPTION

The B<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 interract 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 concurently on a single hardware system where the basic resources are driven by a Linux instance. The library aim at providing long term stable C API initially for the Xen paravirtualization but should be able to integrate other virtualization mechanisms, it currently also support QEmu and KVM.

The basic structure of most virsh usage is:

  virsh <command> <domain-id> [OPTIONS]

Where I<command> is one of the commands listed below, I<domain-id>
is the numeric domain id, or the domain name (which will be internally
translated to domain id), and I<OPTIONS> 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.

The B<virsh> program can be used either to run one command at a time
by giving the command as an argument on the command line, or as a shell
if no command is given in the command line, it will then start a minimal
interpreter waiting for your commands and the B<quit> command will then exit
the program.

=head1 NOTES

All B<virsh> operations rely upon the libvirt library.
For any virsh commands to run xend/qemu, or what ever virtual library that libvirt suports.  For this reason you should start xend/qemu as a service when your system first boots using xen/qemu. This can usually be done using the command
B<service start libvirtd> .

Most B<virsh> commands require root privledges to run due to the
communications channels used to talk to the hypervisor.  Running as
non root will return an error.

Most B<virsh> commands act asynchronously, so just because the B<virsh>
program returned, doesn't mean the action is complete.  This is
important, as many operations on domains, like create and shutdown,
can take considerable time (30 seconds or more) to bring the machine
into a fully compliant state.  If you want to know when one of these
actions has finished you must poll through virsh list periodically.

=head1 GENERIC COMMANDS

The following commands are generic i.e. not specific to a domain.

=over 4

=item B<help> optional I<command>

This prints a small synoposis about all commands available for B<virsh>
B<help> I<command> will print out a detailed help message on that command.

=item B<quit> 

quit this interactive terminal

=item B<version> 

Will print out the major version info about what this built from. 

=over 4

B<Example> 

B<virsh> version 

Compiled against library: libvir 0.0.6 

Using library: libvir 0.0.6

Using API: Xen 3.0.0

Running hypervisor: Xen 3.0.0

=back

=item B<connect> I<URI> optional I<--readonly>

(Re)-Connect to the hypervisor. This is a build-in command after shell
start up, and usually get an I<URI> parameter specifying how to connect
to the hypervisor. The documentation page at L<http://libvirt.org/uri.html>
list the values supported but the most common are:

=over 4

=item xen:///

this is used to connect to the local Xen hypervisor, this is the default

=item qemu:///system

allow to connect locally as root to the daemon supervizing QEmu and KVM domains

=item qemu:///session

allow to connect locally as a normal user to the his own set of QEmu and KVM domains

=back

For remote access see the documetnation page on how to make URIs.
The I<--readonly> option allows for read-only connection

=item B<nodeinfo>

Returns basic information about the node, like number and type of CPU,
and size of the physical memory.

=item B<capabilities>  

Print 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:
  L<http://libvirt.org/format.html#Capa1>

=item B<list>  

Prints information about one or more domains.  If no domains are
specified it prints out information about all domains.

An example format for the list is as follows:

B<virsh> list
 Id Name                 State 

---------------------------------- 

  0 Domain-0             running 
  2 fedora               paused 


Name is the name of the domain.  ID the domain numeric id.  
 State is the run state (see below).  

=over 4

B<STATES>


The State field lists 6 states for a Xen Domain, and which ones the
current Domain is in.

=item B<r - running>

The domain is currently running on a CPU

=item B<b - blocked>

The domain is blocked, and not running or runable.  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.

=item B<p - paused>

The domain has been paused, usually occurring through the administrator
running B<xm pause>.  When in a paused state the domain will still
consume allocated resources like memory, but will not be eligible for
scheduling by the Xen hypervisor.

=item B<s - shutdown>

The 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.

=item B<c - crashed>

The 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.  See L<xmdomain.cfg> for more info.

=item B<d - dying>

The domain is in process of dying, but hasn't completely shutdown or
crashed.

=back

=head1 DOMAIN COMMANDS

The following commands manipulate domains directly, as stated
previously most commands take domain-id as the first parameter. The
I<domain-id> can be specified as an short integer, a name or a full UUID.

=over 4

=item B<autostart> optional I<--disable> I<domain-id>

Configure a domain to be automatically started at boot.

The option I<--disable> disable autostarting.

=item B<console> I<domain-id>

Connect the virtual serial console for the guest.

=item B<create> I<FILE> 

Create a domain from an XML <file> an easy way to create one if you have a pre-existing xen guest created via B<xm> create <XMLFILE>. 

B<Example>

virsh dumpxml <domain-id> > file. 

=item B<define> I<FILE>

Define a domain from an XML <file>. The domain definitions is registered
but not started.

=item B<destroy> I<domain-id>

Immediately terminate the domain domain-id.  This doesn't give the domain
OS any chance to react, and it the equivalent of ripping the power
cord out on a physical machine.  In most cases you will want to use
the B<shutdown> command instead.

=item B<dominfo> I<domain-id> 

Returns basic information about the domain.

=item B<domuuid> I<domain-name-or-id>

Convert a domain name or id to domain UUID

=item B<domid> I<domain-name>

Converts a domain name to a domain id using xend's internal mapping.

=item B<dominfo> I<domain-id>

Returns basic information about the domain.

=item B<domname> I<domain-id>

convert a domain Id to domain name

=item B<domstate> I<domain-id>

Returns state about a running domain.

=item B<dumpxml> I<domain-id>

Ouput the domain informations as an XML dump to stdout, this format can be used by the B<create> command. 


=item B<reboot> I<domain-id>

Reboot a domain.  This acts just as if the domain had the B<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.

For xen vm the behavior of what happens to a domain when it reboots is set by the
I<on_reboot> parameter of the xmdomain.cfg file when the domain was
created.

=item B<restore> I<state-file>

Restores a domain from an B<virsh save> state file.  See I<save> for more info.

=item B<save> I<domain-id> I<state-file>

Saves a running domain 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.  B<virsh restore> restores from this state file.

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.

=item B<setmem> I<domain-id> B<kilobytes>

Change the current memory allocation in the guest domain. This should take
effect immediately. The memory limit is specified in
kilobytes.

=item B<setmaxmem> I<domain-id> B<kilobytes>

Change the maximum memory allocation limit in the guest domain. This should
not change the current memory use. The memory limit is specified in 
kilobytes.

=item B<setvcpus> I<domain-id> I<count>

Change the number of virtual CPUs active in the guest domain. Note that
I<count> may be limited by host, hypervisor or limit coming from the 
original description of domain.

=item B<shutdown> I<domain-id>

Gracefully shuts down a domain.  This coordinates with the domain OS
to perform graceful shutdown, so there is no guaruntee that it will
succeed, and may take a variable length of time depending on what
services must be shutdown in the domain.  

For a xen guest vm the behavior of what happens to a domain when it reboots is set by the
I<on_shutdown> parameter of the xmdomain.cfg file when the domain was
created.

=item B<suspend> I<domain-id>

Suspend a running domain. It is kept in memory but won't be scheduled
anymore.

=item B<resume> I<domain-id>

Moves a domain out of the suspended state.  This will allow a previously
suspended domain to now be eligible for scheduling by the the underlying
hypervisor.

=item B<undefine> I<domain-id>

Undefine the configuration for an inactive domain. Since it's not running
the domain name or UUId must be used as the I<domain-id>.

=item B<vcpuinfo> I<domain-id>

Returns basic information about the domain virtual CPUs, like the number of
vCPUs, the running time, the affinity to physical processors.

=item B<vcpupin> I<domain-id> I<vcpu> I<cpulist>

Pin domain VCPUs to host physical CPUs. The I<vcpu> number must be provided
and I<cpulist> is a comma separated list of physical CPU numbers.

=item B<vncdisplay> I<domain-id>

Output the IP address and port number for the VNC display.

=back

=head1 DEVICES COMMANDS

The following commands manipulate devices associated to domains.
The domain-id can be specified as an short integer, a name or a full UUID.
To better understand the values allowed as options for the command
reading the documentation at L<http://libvirt.org/format.html> on the
format of the device sections to get the most accurate set of accepted values.

=over 4

=item B<attach-device> I<domain-id> I<FILE>

Attach a device to the domain, using a device definition in an XML file.
See the documentation to learn about libvirt XML format for a device.

=item B<attach-disk> I<domain-id> I<source> I<target> optional I<--driver driver> I<--subdriver subdriver> I<--type type> I<--mode mode>

Attach a new disk device to the domain.
I<source> and I<target> are paths for the files and devices.
I<driver> can be I<file>, I<tap> or I<phy> depending on the kind of access.
I<type> can indicate I<cdrom> or I<floppy> as alternative to the disk default.
I<mode> can specify the two specific mode I<readonly> or I<shareable>.

=item B<attach-interface> I<domain-id> I<type> I<source> optional I<--target target> I<--mac mac> I<--script script>

Attach a new network interface to the domain.
I<type> can be either I<network> to indicate a physical network device or I<bridge> to indicate a bridge to a device.
I<source> indicates the source device.
I<target> allows to indicate the target device in the guest.
I<mac> allows to specify the MAC address of the network interface.
I<script> allows to specify a path to a script handling a bridge instead of
the default one.

=item B<detach-device> I<domain-id> I<FILE>

Detach a device from the domain, takes the same kind of XML descriptions
as command B<attach-device>.

=item B<detach-disk> I<domain-id> I<target>

Detach a disk device from a domain. The I<target> is the device as seen
from the domain.

=item B<detach-interface> I<domain-id> I<type> optional I<--mac mac>

Detatch a network interface from a domain.
I<type> can be either I<network> to indicate a physical network device or I<bridge> to indicate a bridge to a device.
It is recommended to use the I<mac> option to distinguish between the interfaces
if more than one are present on the domain.

=back

=head1 VIRTUAL NETWORKS 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 dvices. For more detailed informations about this feature
see the documentation at L<http://libvirt.org/format.html#Net1> . A lot
of the command for virtual networks are similar to the one used for domains,
but the way to name a virtual network is either by its name or UUID.

=over 4

=item B<net-autostart> I<network> optional I<--disable>

Configure a virtual network to be automatically started at boot.
The I<--disable> option disable autostarting.

=item B<net-create> I<file>

Create a virtual network from an XML I<file>, see the documentation to get
a description of the XML network format used by libvirt. 

=item B<net-define> I<file>

Define a virtual network from an XML I<file>, the network is just defined but
not instanciated.

=item B<net-destroy> I<network>

Destroy a given virtual network specified by its name or UUID. This takes
effect immediately.

=item B<net-dumpxml> I<network>

Output the virtual network information as an XML dump to stdout.

=item B<net-list> optional I<--inactive> or I<--all>

Returns the list of active networks, if I<--all> is specified this will also
include defined but inactive networks, if I<--inactive> is specified only the
inactive ones will be listed.

=item B<net-name> I<network-UUID>

Convert a network UUID to network name.

=item B<net-start> I<network>

Start a (previously defined) inactive network.

=item B<net-undefine> I<network>

Undefine the configuration for an inactive network.

=item B<net-uuid> I<network-name>

Convert a network name to network UUID.

=back

=head1 SEE ALSO

L<xm(1)>, L<xmdomain.cfg(5)>, L<xentop(1)> , L<http://www.libvirt.org/>

=head1 AUTHOR

  Andrew Puch <apuch @ redhat.com> 
  Daniel Veillard <veillard @ redhat.com>

  Based on the xm man paged by 
  Sean Dague <sean at dague dot net>
  Daniel Stekloff <dsteklof at us dot ibm dot com>


=head1 BUGS

Bugs can be view on the RedHat buzilla page under the libvirt 
L<https://bugzilla.redhat.com/>

L<https://bugzilla.redhat.com/bugzilla/buglist.cgi?product=Fedora+Core&component=libvirt&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&bug_status=MODIFIED&short_desc_type=allwordssubstr&short_desc=&long_desc_type=allwordssubstr>
 
=end