When disk snapshots were first implemented, libvirt blindly refused
to allow an external snapshot destination that already exists, since
qemu will blindly overwrite the contents of that file during the
snapshot_blkdev monitor command, and we don't like a default of
data loss by default. But VDSM has a scenario where NFS permissions
are intentionally set so that the destination file can only be
created by the management machine, and not the machine where the
guest is running, so that libvirt will necessarily see the destination
file already existing; adding a flag will allow VDSM to force the file
reuse without libvirt complaining of possible data loss.
https://bugzilla.redhat.com/show_bug.cgi?id=767104
* include/libvirt/libvirt.h.in (virDomainSnapshotCreateFlags): Add
VIR_DOMAIN_SNAPSHOT_CREATE_REUSE_EXT.
* src/libvirt.c (virDomainSnapshotCreateXML): Document it. Add
note about partial failure.
* tools/virsh.c (cmdSnapshotCreate, cmdSnapshotCreateAs): Add new
flag.
* tools/virsh.pod (snapshot-create, snapshot-create-as): Document
it.
* src/qemu/qemu_driver.c (qemuDomainSnapshotDiskPrepare)
(qemuDomainSnapshotCreateXML): Implement the new flag.
Add a new command domiftune to get/set interface parameters.
* tools/virsh.c: implement the new command
* tools/virsh.pod: documentation of the new command
Virsh's echo command looks not having any relations with domains and its
description should go into the generic commands section instead of the
domain commands section (current).
Virsh's send-key command manipulates domains and its description should
go into the domain commands section instead of generic commands section
(current).
Add an option for virsh undefine command, to remove associated storage
volumes while undefining a domain. This patch allows the user to remove
associated (libvirt managed ) storage volumes while undefining a domain.
The new option --storage for the undefine command takes a string
argument that consists of comma separated list of target or source path
of volumes to be undefined. Volumes are removed after the domain has
been successfully undefined,
If a volume is not part of a storage pool, the user is warned to remove
the volume in question himself.
Option --wipe-storage may be specified along with this, that ensures
the image is wiped before removing.
Option --remove-all-storage enables the user to remove all storage. The
name is chosen long as the users should be aware what they're about to
do.
I was wondering why 'virsh edit' didn't support the same
'--inactive' option as 'virsh dumpxml'; reading the source
code showed that --inactive was already implied, and that
the only way to alter a running guest rather than affecting
next boot is by hot-plugging individual devices, or by
something complex like saving the guest and modifying the
save image.
* tools/virsh.pod (define, edit): Mention behavior when guest is
already running.
Currently virsh supports only ^] as escape character for console.
However, some users might want to use something else. This patch
creates such ability by specifying '-e' switch on virsh command
line.
Prior to this patch, for a running dom, the commands:
$ virsh blkiotune dom --device-weights /dev/sda,502,/dev/sdb,498
$ virsh blkiotune dom --device-weights /dev/sda,503
$ virsh blkiotune dom
weight : 500
device_weight : /dev/sda,503
claim that /dev/sdb no longer has a non-default weight, but
directly querying cgroups says otherwise:
$ cat /cgroup/blkio/libvirt/qemu/dom/blkio.weight_device
8:0 503
8:16 498
After this patch, an explicit 0 is required to remove a device path
from the XML, and omitting a device path that was previously
specified leaves that device path untouched in the XML, to match
cgroups behavior.
* src/qemu/qemu_driver.c (parseBlkioWeightDeviceStr): Rename...
(qemuDomainParseDeviceWeightStr): ...and use correct type.
(qemuDomainSetBlkioParameters): After parsing string, modify
rather than replacing existing table.
* tools/virsh.pod (blkiotune): Tweak wording.
Support virsh command blkdeviotune. Can set or query a block disk
I/O throttle setting.
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
This adds per-device weights to <blkiotune>. Note that the
cgroups implementation only supports weights per block device,
and not per-file within the device; hence this option must be
global to the domain definition rather than tied to individual
<devices>/<disk> entries:
<domain ...>
<blkiotune>
<device>
<path>/path/to/block</path>
<weight>1000</weight>
</device>
</blkiotune>
..
This patch also adds a parameter --device-weights to virsh command
blkiotune for setting/getting blkiotune.weight_device for any
hypervisor that supports it. All <device> entries under
<blkiotune> are concatenated into a single string attribute under
virDomain{Get,Set}BlkioParameters, named "device_weight".
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
One of the top questions by libvirt users is how to create a host
bridge device so that guests can be directly on the physical
network. There are several example documents that explain how to do
this manually, but following them often results in confusion and
failure. virt-manager does a good job of creating a bridge based on an
existing network device, but not everyone wants to use virt-manager.
This patch adds a new command, iface-bridge that makes it just about
as simple as possible to create a new bridge device based on an
existing ethernet/vlan/bond device (including associating IP
configuration with the bridge rather than the now-attached device),
and start that new bridge up ready for action, eg:
virsh iface-bridge eth0 br0
For symmetry's sake, it also adds a command to remove a device from a
bridge, restoring the IP config to the now-unattached device:
virsh iface-unbridge br0
(I had a short debate about whether to do "iface-unbridge eth0"
instead, but that would involve searching through all bridge devices
for the one that contained eth0, which seems like a bit too much
trouble).
NOTE: These two commands require that the netcf library be available
on the host. Hopefully this will provide some extra incentive for
people using suse, debian, ubuntu, and other similar systems to polish
up (and push downstream) the ports to those distros recently pushed to
the upstream netcf repo by Dan Berrange. Anyone interested in helping
with that effort in any way should join the netcf-devel mailing list
(subscription info at
https://fedorahosted.org/mailman/listinfo/netcf-devel)
During creation of the bridge, it's possible to specify whether or not
the STP protocol should be started up on the bridge and, if so, how
many seconds the bridge should squelch traffic from newly added
devices while learning new topology (defaults are stp='on' and
delay='0', which seems to usually work best for bridges used in the
context of libvirt guests).
There is also an option to not immediately start the bridge (and a
similar option to not immediately start the un-attached device after
destroying the bridge. Default is to start the new device, because in
the case of iface-unbridge not starting is strongly discouraged as it
will leave the system with no network connectivity on that interface
(because it's necessary to destroy/undefine the bridge device before
the unattached device can be defined), and it seemed better to make
the option for iface-bridge behave consistently.
NOTE TO THOSE TRYING THESE COMMANDS FOR THE FIRST TIME: to guard
against any "unexpected" change to configuration, it is advisable to
issue an "virsh iface-begin" command before starting any interface
config changes, and "virsh iface-commit" only after you've verified
that everything is working as you expect. If something goes wrong,
you can always run "virsh iface-rollback" or reboot the system (which
should automatically do iface-rollback).
Aside from adding the code for these two functions, and the two
entries into the command table, the only other change to virsh.c was
to add the option name to vshCommandOptInterfaceBy(), because the
iface-unbridge command names its interface option as "bridge".
virsh.pod has also been updated with short descriptions of these two
new commands.
Clarify some of the effects of managed passthrough <hostdev> devices;
with recent changes (commit d093547), a nodedev-reattach is only needed
to pair up to an explicit nodedev-dettach (but beware that older
virt-manager has a bug where it uses explicit nodedev-dettach under the
hood when using the gui to hotplug a hostdev device).
* docs/formatdomain.html.in: Mention reattach.
* tools/virsh.pod (nodedev): Mention managed mode.
Rather than having to do:
$ virsh snapshot-revert dom $(virsh snapshot-current dom --name)
I thought it would be nice to do:
$ virsh snapshot-revert dom --current
I didn't add 'virsh snapshot-dumpxml --current' since we already have
'virsh snapshot-current' for the same task. snapshot-list accepted
a name but did not require it, and that remains the case, with
--current serving in place of that name. For all other commands,
name used to be required, and can now be replaced by --current;
I intentionally made it so that omitting both --current and a name
is an error (having the absence of a name imply --current seems
just a bit too magic, so --current must be explicit). I also had
to keep snapshot-edit backwards-compatible, as the only command
that already had a --current argument alongside a name, which still
works to both edit a named snapshot and make it current.
* tools/virsh.c (vshLookupSnapshot): New helper function.
(cmdSnapshotEdit, cmdSnapshotList, cmdSnapshotParent)
(cmdSnapshotDelete, cmdDomainSnapshotRevert): Use it, adding an
option where needed.
* tools/virsh.pod (snapshot-delete, snapshot-edit)
(snapshot-list, snapshot-parent, snapshot-revert): Document
use of --current.
(snapshot-dumpxml): Mention alternative.
Sometimes, we only care about one branch of the snapshot hierarchy.
Make it easier to list a single branch, by using the new APIs.
Technically, I could emulate these new virsh options on old servers
by doing a complete dump, then scraping xml to filter out just the
snapshots that I care about, but I didn't want to do that in this patch.
* tools/virsh.c (cmdSnapshotList): Add --from, --descendants.
* tools/virsh.pod (snapshot-list): Document them.
I was a bit surprised that 'virsh snapshot-edit dom name' silently
allowed me to clone things, while still telling me the old name,
especially since other commands like 'virsh edit dom' reject rename
attempts (*). This fixes things to be more explicit (**).
(*) Technically, 'virsh edit dom' relies on virDomainDefineXML
behavior, which rejects attempts to mix a new name with existing
uuid or new uuid with existing name, but you can create a new
domain by changing both uuid and name. On the other hand, while
snapshot-edit --clone is a true clone, creating a new domain
would also have to decide whether to clone snapshot metadata,
managed save, and any other secondary data related to the domain.
Domain renames are not trivial either.
(**) Renaming or creating a clone is still a risky proposition -
for offline snapshots and system checkpoints, if the new name
does not match an actual name recorded in the qcow2 internal
snapshots, then you cannot revert to the new checkpoint. But it
is assumed that anyone using the new virsh flags knows what they
are doing, and can deal with the fallout caused by a rename/clone;
that is, we can't completely prevent a user from shooting
themselves in the foot, so much as we are making the default
action less risky.
* tools/virsh.c (cmdSnapshotEdit): Add --rename, --clone.
* tools/virsh.pod (snapshot-edit): Document them.
Although reverting to a snapshot is a form of data loss, this is
normally expected. However, there are two cases where additional
surprises (failure to run the reverted state, or a break in
connectivity to the domain) can come into play. Requiring extra
acknowledgment in these cases will make it less likely that
someone can get into an unrecoverable state due to a default revert.
Also create a new error code, so users can distinguish when forcing
would make a difference, rather than having to blindly request force.
* include/libvirt/libvirt.h.in (VIR_DOMAIN_SNAPSHOT_REVERT_FORCE):
New flag.
* src/libvirt.c (virDomainRevertToSnapshot): Document it.
* include/libvirt/virterror.h (VIR_ERR_SNAPSHOT_REVERT_RISKY): New
error value.
* src/util/virterror.c (virErrorMsg): Implement it.
* tools/virsh.c (cmdDomainSnapshotRevert): Add --force to virsh.
* tools/virsh.pod (snapshot-revert): Document it.
This patch is based on a improvement suggested by Kazuhiro Kikuchi
of Fujitsu, it gives a description of the target parameter for that
command
* tools/virsh.pod: add description for target parameter of
attach-interface
The man page suggest that the cpu_shares parameter of schedinfo
allows values 0-262144, but the kernel remaps values 0 and 1 to
the minimum 2, just document that behaviour:
[root@test ~]# cat /cgroup/cpu/libvirt/qemu/cpu.shares
1024
[root@test ~]# echo 0 > /cgroup/cpu/libvirt/qemu/cpu.shares
[root@test ~]# cat /cgroup/cpu/libvirt/qemu/cpu.shares
2
[root@test ~]# echo 1 > /cgroup/cpu/libvirt/qemu/cpu.shares
[root@test ~]# cat /cgroup/cpu/libvirt/qemu/cpu.shares
2
[root@test ~]#
* tools/virsh.pod: update description of the cpu_shares parameter
to indicate the values 0 and 1 are automatically changed by the
kernel to minimal value 2
Reuse the tree listing of nodedev-list, coupled with the new helper
function to efficiently grab snapshot parent names, to produce
tree output for a snapshot hierarchy. For example:
$ virsh snapshot-list dom --tree
root1
|
+- sibling1
+- sibling2
| |
| +- grandchild
|
+- sibling3
root2
|
+- child
* tools/virsh.c (cmdSnapshotList): Add --tree.
* tools/virsh.pod (snapshot-list): Document it.
This section of the man page was completely missing; I stumbled on
it when I had no clue that I had to use nodedev-reattach after
I was done playing with <hostdev> device passthrough to one of my
guests.
* tools/virsh.pod (NODEDEV COMMANDS): New section.
(attach-device, detach-device): Add cross-references.
pod2man from perl-5.8.8 (RHEL 5) errors out on ill-formed POD:
*** ERROR: unterminated I<...> at line 1114 in file virsh.pod
*** ERROR: unterminated I<...> at line 1851 in file virsh.pod
Newer pod2man appears to be more tolerant (which is a shame,
because it meant that this error is harder to detect).
* tools/virsh.pod (undefine, snapshot-current): Add missing >.
Some virsh commands start a (long-running) job that can be monitored
using domjobinfo and aborted with domjobabort. Let's be explicit about
this in virsh man page.
QEMU 0.13 introduced cache=unsafe for -drive, this patch exposes
it in the libvirt layer.
* Introduced a new QEMU capability flag ($prefix_CACHE_UNSAFE),
as even if $prefix_CACHE_V2 is set, we can't know if unsafe
is supported.
* Improved the reliability of qemu cache type detection.
Commit 0a22f54 added --min-guarantee option for the memtune command.
This option is supported only by the ESX hypervisor. This patch adds a
statement about this fact, to prevent user confusion.
This patch also adds explanation how to clear/set to unlimited the
memory tunables. (documments the -1 value).
Virsh man page lists driver types to be used with attach-device
command, but does not specify that those are usable only with the XEN
Hypervisor.
This patch adds statement, that those options specified are applicable
only on the Xen hypervisor and adds option usable with qemu emulator.
This patch also changes type of error returned by QEMU driver if the
user specifies incompatible driver type from VIR_ERR_INTERNAL_ERROR to
VIR_ERR_CONFIG_UNSUPPORTED.
Users of virsh complain that output of the domblkstat command
is not intuitive enough. This patch adds explanation of fields
returned by this command to the help section for domblkstat and
the man page of virsh. Also a switch --human is added for
domblkstat that prints the fields with more descriptive
texts.
This patch also changes sequence of the output fields and their
names back to the order and spelling established by previous
versions of virsh to maintain compatibility with scripts.
Example of ordered and "translated" output:
PRE-patch:
virsh # domblkstat 1 vda
vda wr_bytes 5170176
vda wr_operations 511
vda rd_bytes 82815488
vda rd_operations 3726
POST-patch:
virsh # domblkstat 1 vda
vda rd_req 3726
vda rd_bytes 82815488
vda wr_req 478
vda wr_bytes 4965376
Example of human readable output:
virsh # domblkstat 1 vda --human
Device: vda
number of read operations: 3726
number of read bytes: 82815488
number of write operations: 478
number of bytes written: 4965376
https://bugzilla.redhat.com/show_bug.cgi?id=731656
Documentation did not specify, that some permissions are required on
target path for coredump for the user running the hypervisor.
Diff to v1:
- reword statements
With this patch, it is hopefully a bit more obvious that for
snapshot-create-as, a literal '--diskspec' is mandatory if name
or description was omitted, but optional if all earlier options
were provided.
These all denote two diskspecs and a description:
virsh snapshot-create-as dom name desc vda vdb
virsh snapshot-create-as dom name desc --diskspec vda --diskspec vdb
virsh snapshot-create-as dom name desc --diskspec vda vdb
virsh snapshot-create-as dom name desc vda --diskspec vdb
virsh snapshot-create-as dom --diskspec vda --diskspec vdb name desc
This gives two diskspecs but no description:
virsh snapshot-create-as dom name --diskspec vda --diskspec vdb
And this treats 'vda' as the description, with only one diskspec:
virsh snapshot-create-as dom name vda vdb
The help output now shows:
snapshot-create-as <domain> [<name>] [<description>] [--print-xml] [--no-metadata] [--halt] [--disk-only] [[--diskspec] <string>]...
I also checked the help output for echo and send-key, which are two
other variants of argv commands.
* tools/virsh.pod (snapshot-create-as): Document when a literal
--diskspec must preceed a diskspec argument.
* tools/virsh.c (vshCmddefHelp): Update help output for argv when
naming the option is useful.
(vshCmddefGetData): Fix logic on when argv was seen.
* tests/virsh-optparse: Add tests to avoid regressions.
Two new commands are added to virsh that wrap usage of
virDomainUpdateDeviceFlags for changing link state of domain's network
interfaces. These wrappers extract network devices's xml configuration
and modify the link state for easy manipulation from an user's perspective.
- domif-setlink - set link state of a domains virtual network interface
- domif-getlink - get link state
* tools/virsh.c - Add functionality to virsh
* tools/virsh.pod - Manpage documentation
Expose the disk-only flag through virsh. Additionally, make
virsh snapshot-create-as take an arbitrary number of diskspecs,
which can be used to build up the xml for <domainsnapshot>.
* tools/virsh.c (cmdSnapshotCreate): Add --disk-only.
(cmdSnapshotCreateAs): Likewise, and add argv diskspec.
(vshParseSnapshotDiskspec): New helper function.
(vshCmddefGetOption): Allow naming of argv field.
* tools/virsh.pod (snapshot-create, snapshot-create-as): Document
them.
* tests/virsh-optparse: Test snapshot-create-as parsing.
This adds a convenience function to virsh that parses out block
information from the domain xml, making it much easier to see
what strings can be used in all other contexts that demand a
specific block name, especially when given the previous patch
that allows using either target or unique source name.
As an example on a domain with one disk and an empty cdrom drive:
Target Source
-------------------------------------------
vda /var/lib/libvirt/images/fedora_12.img
hdc -
* tools/virsh.c (cmdDomblklist): New function.
* tools/virsh.pod (domblklist): Document it.
I got confused when 'virsh domblkinfo dom disk' required the
path to a disk (which can be ambiguous, since a single file
can back multiple disks), rather than the unambiguous target
device name that I was using in disk snapshots. So, in true
developer fashion, I went for the best of both worlds - all
interfaces that operate on a disk (aka block) now accept
either the target name or the unambiguous path to the backing
file used by the disk.
* src/conf/domain_conf.h (virDomainDiskIndexByName): Add
parameter.
(virDomainDiskPathByName): New prototype.
* src/libvirt_private.syms (domain_conf.h): Export it.
* src/conf/domain_conf.c (virDomainDiskIndexByName): Also allow
searching by path, and decide whether ambiguity is okay.
(virDomainDiskPathByName): New function.
(virDomainDiskRemoveByName, virDomainSnapshotAlignDisks): Update
callers.
* src/qemu/qemu_driver.c (qemudDomainBlockPeek)
(qemuDomainAttachDeviceConfig, qemuDomainUpdateDeviceConfig)
(qemuDomainGetBlockInfo, qemuDiskPathToAlias): Likewise.
* src/qemu/qemu_process.c (qemuProcessFindDomainDiskByPath):
Likewise.
* src/libxl/libxl_driver.c (libxlDomainAttachDeviceDiskLive)
(libxlDomainDetachDeviceDiskLive, libxlDomainAttachDeviceConfig)
(libxlDomainUpdateDeviceConfig): Likewise.
* src/uml/uml_driver.c (umlDomainBlockPeek): Likewise.
* src/xen/xend_internal.c (xenDaemonDomainBlockPeek): Likewise.
* docs/formatsnapshot.html.in: Update documentation.
* tools/virsh.pod (domblkstat, domblkinfo): Likewise.
* docs/schemas/domaincommon.rng (diskTarget): Tighten pattern on
disk targets.
* docs/schemas/domainsnapshot.rng (disksnapshot): Update to match.
* tests/domainsnapshotxml2xmlin/disk_snapshot.xml: Update test.
Easy enough to emulate even with older servers.
* tools/virsh.c (cmdSnapshotCreate, cmdSnapshotCreateAs): Add
--halt flag.
(vshSnapshotCreate): Emulate halt when flag is unsupported.
* tools/virsh.pod (snapshot-create, snapshot-create-as): Document
it.
