云计算IAAS层-KVM虚拟化 virsh的帮助手册
·
VIRSH(1) Virtualization Support VIRSH(1)
NAME
virsh - management user interface
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 cur‐
rent 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 identi‐
fied by domain id. In other words, if a numeric value is supplied it will be inter‐
preted 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 ar‐
gument consisting of multiple COMMAND actions and their arguments joined with white‐
space and separated by semicolons or newlines between commands, where unquoted back‐
slash-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 (de‐
fault). See the documentation of VIRSH_DEBUG environment variable below for the de‐
scription of each LEVEL.
• -e, --escape string
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-interval INTERVAL
Set an INTERVAL (in seconds) for sending keepalive messages to check whether connec‐
tion to the server is still alive. Setting the interval to 0 disables client
keepalive mechanism.
• -K, --keepalive-count COUNT
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, --log FILE
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 al‐
ready 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 com‐
plete and you must poll periodically to detect that the guest completed the opera‐
tion.
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 de‐
fault to bytes, while other commands default to kibibytes). The following case-in‐
sensitive 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 1,152,921,504,606,846,976
GENERIC 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 URI
To 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 domains
quit, exit
Syntax:
quit
exit
quit 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: 1.2.6
cd
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:
pwd
Will print the current directory.
connect
Syntax:
connect [URI] [--readonly]
(Re)-Connect to the hypervisor. When the shell is first started, this is automati‐
cally 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:
uri
Prints the hypervisor canonical URI, can be useful in shell mode.
hostname
Syntax:
hostname
Print the hypervisor hostname.
sysinfo
Syntax:
sysinfo
Print the XML representation of the hypervisor sysinfo, if available.
nodeinfo
Syntax:
nodeinfo
Returns 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 speci‐
fied cell statistics only.
nodesevinfo
Syntax:
nodesevinfo
Reports 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 du‐
ration 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 mem‐
ory 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:
capabilities [--xpath EXPRESSION] [--wrap]
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:
https://libvirt.org/formatcaps.html
The XML also show the NUMA topology information if available.
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
domcapabilities
Syntax:
domcapabilities [virttype] [emulatorbin] [arch] [machine]
[--xpath EXPRESSION] [--wrap]
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 do‐
main 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 capa‐
bilities 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 ca‐
pabilities output. The arch option specifies the architecture to be used for the do‐
main. 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 capabil‐
ities 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 ma‐
chine. Supplying a machine value will generate output for the specific machine.
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
pool-capabilities
Syntax:
pool-capabilities
Print 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 domain
Inject 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 paused
Name 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:
• running
The domain is currently running on a CPU
• idle
The 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.
• paused
The domain has been paused, usually occurring through the administrator running
virsh suspend. When in a paused state the domain will still consume allocated re‐
sources like memory, but will not be eligible for scheduling by the hypervisor.
• in 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.
• shut off
The domain is not running. Usually this indicates the domain has been shut down
completely, or has not been started.
• 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.
• pmsuspended
The 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 in‐
clude transient guests specify --transient.
Existence of managed save image
To list domains having a managed save image specify flag --with-managed-save. For do‐
mains 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 fea‐
ture 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 pos‐
sible 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 pos‐
sible 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 paused
freecell
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 to‐
tal 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 argu‐
ment 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). Alterna‐
tively, 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 hy‐
pervisor.) 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 com‐
mand. 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 con‐
tents from domain XML definition or the CPU definition created from the host CPU
model found in domain capabilities XML (printed by domcapabilities command). In addi‐
tion 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 incom‐
patible 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 doc‐
ument against an internal RNG schema.
cpu-models
Syntax:
cpu-models arch
Print 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 do‐
main capabilities XML returned by domcapabilities command. Moreover, for some archi‐
tectures libvirt does not know any CPU models and the usable CPU models are only lim‐
ited 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 defini‐
tion 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 ca‐
pabilities XML containing the CPU definition. For more information on guest CPU defi‐
nition 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 ma‐
chine 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 for‐
mat of the XML document against an internal RNG schema.
hypervisor-cpu-baseline
Syntax:
hypervisor-cpu-baseline [FILE] [virttype] [emulator] [arch] [machine]
[--features] [--migratable] [model]
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.)
As an alternative for FILE in case the XML would only contain a CPU model with no ad‐
ditional features the CPU model name itself can be passed as model. Exactly one of
FILE and model must be used.
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 capabili‐
ties XMLs containing the CPU definitions. It is recommended to use only the CPU defi‐
nitions from domain capabilities, as on some architectures using the host CPU defini‐
tion 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, run‐
ning the virsh hypervisor-cpu-baseline command with no additional options on the re‐
sult of virsh domcapabilities will transform the host CPU model from domain capabili‐
ties XML to a form directly usable in domain XML. Running the command with model (or
FILE containing just a single CPU definition with model and no feature elements)
which is marked as unusable in virsh domcapabilities will provide a list of features
that block this CPU model from being usable.
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 ma‐
chine type. If --features is specified, then the resulting XML description will ex‐
plicitly 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 com‐
mands take domain as the first parameter. The domain can be specified as a short in‐
teger, a name or a full UUID.
autostart
Syntax:
autostart [--disable] domain
Configure 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 spec‐
ifies 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 be‐
ing 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 sec‐
ond 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 speci‐
fied. --write-bytes-sec-max specifies maximum write throughput limit as a scaled in‐
teger, the default being bytes per second if no suffix is specified. --to‐
tal-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. --to‐
tal-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 speci‐
fies 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 mul‐
tiple 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 ei‐
ther --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 de‐
vice 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/de‐
vice,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 re‐
main 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/de‐
vice,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/de‐
vice,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 ei‐
ther --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 at‐
tempts 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 ren‐
dered 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 block‐
job. However, if --wait is specified, then this command will block until the opera‐
tion 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 up‐
dates. 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). band‐
width 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] [--print-xml]
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> ele‐
ment 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 visi‐
ble 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. Ini‐
tially, 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 sec‐
onds 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 addition‐
ally 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 band‐
width 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 al‐
lows fine-tuning of the granularity that will be copied when a dirty region is de‐
tected; 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 recov‐
ered 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 im‐
pact performance of writes while the blockjob is running.
If --print-xml is specified, then the XML used to start the block copy job is printed
instead of starting the job.
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 sup‐
ply bytes/s resolution; when omitting the flag, raw output is listed in MiB/s and hu‐
man-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 nega‐
tive value is interpreted as an unsigned long value or essentially unlimited. The hy‐
pervisor 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 interme‐
diate 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 SIG‐
INT is sent (usually with Ctrl-C). Using --verbose along with --wait will produce
periodic status updates. If job cancellation is triggered, --async will return con‐
trol 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). band‐
width 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 ([size] | [--capacity])
Resize a block device of domain while the domain is running, path specifies the abso‐
lute 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 at‐
tached to domain (see also domblklist for listing these names).
For image formats without metadata (raw) stored inside fixed-size storage (e.g.
block devices) the --capacity flag can be used to resize the device to the full size
of the backing device.
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] [--resume]
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 config‐
ured 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 sup‐
ports safe console handling. This flag specifies that the server has to ensure exclu‐
sive access to console devices. Optionally the --force flag may be specified, re‐
questing to disconnect any existing sessions, such as in a case of a broken connec‐
tion.
If the flag --resume is specified then the guest is resumed after connecting to the
console.
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 per‐
sistent guests that will run with one-time use configuration, leaving the persistent
XML untouched (this can come handy during an automated testing of various configura‐
tions 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 de‐
stroyed 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 de‐
scriptors 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-ini‐
tialized from its pristine template.
Example:
1. prepare a template from an existing domain (skip directly to 3a if writing one
from scratch)
# virsh dumpxml <domain> > domain.xml
2. edit the template using an editor of your choice and:
a. DO CHANGE! <name> and <uuid> (<uuid> can also be removed), or
b. DON'T CHANGE! either <name> or <uuid>
# $EDITOR domain.xml
3. create a domain from domain.xml, depending on whether following 2a or 2b respec‐
tively:
a. the domain is going to be transient
b. 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 def‐
initions of the domain. If both --live and --config are specified, the --config op‐
tion takes precedence on getting the current description and both live configuration
and config are updated while setting the description. --current is exclusive and im‐
plied if none of these was specified.
Flag --edit specifies that an editor with the contents of current description or ti‐
tle 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 dis‐
played instead of being modified.
destroy
Syntax:
destroy domain [--graceful] [--remove-logs]
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 ma‐
chine. 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 per‐
sistent, 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. Simi‐
larly, the metadata of any checkpoints will be lost, but can be restored with check‐
point-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.
If --remove-logs is specified, remove per domain log files. Not all deployment con‐
figuration can be supported.
In case of QEMU the flag is only supported if virlogd is used to handle QEMU process
output. Otherwise the flag is ignored.
domblkerror
Syntax:
domblkerror domain
Show 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 tar‐
get 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 do‐
main. 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 re‐
quire 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 threshold
Set 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 domain
Returns 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>]
--mode=[page-sampling | dirty-bitmap | dirty-ring]
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. These three page-sampling, dirty-bitmap,
dirty-ring modes are mutually exclusive and alternative when specify calculation
mode, page-sampling is the default mode if missing. The calculated dirty rate infor‐
mation 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 snap‐
shots.
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 filesys‐
tems automatically to keep snapshots consistent. domfsfreeze command is only needed
when a user wants to utilize the native snapshot features of storage devices not sup‐
ported by libvirt.
domfsinfo
Syntax:
domfsinfo domain
Show 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 domfs‐
freeze 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 dis‐
cards blocks which are not in use by the filesystem. If --minimum bytes is speci‐
fied, 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 unspec‐
ified, driver returns the default method available (some drivers support only one
type of source).
domid
Syntax:
domid domain-name-or-uuid
Convert 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] [--print-xml]
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.
If --print-xml is specified, then the XML used to update the interface is printed in‐
stead.
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 inter‐
face 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 domaincheck‐
point 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 [--xpath EXPRESSION] [--wrap] domain
Output XML describing the current backup job.
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
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-device
Get 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 ad‐
dress. Please note, for an unmanaged ethernet type returned stats might have RX/TX
swapped.
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. aver‐
age,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 documenta‐
tion at https://libvirt.org/formatnetwork.html#quality-of-service.
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 ei‐
ther --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 domain
Returns basic information about the domain.
domjobabort
Syntax:
domjobabort domain [--postcopy]
Abort the currently running domain job.
When the job to be aborted is a migration which entered post-copy mode, it cannot be
aborted as none of the hosts involved in migration has a complete state of the do‐
main. Optional --postcopy can be used to interrupt such migration although doing so
may effectively suspend the domain until the migration is resumed (see also --post‐
copy-resume option of migrate).
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 automat‐
ically 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 with‐
out 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 irrel‐
evant unless both source and destination hosts have synchronized time (i.e., NTP dae‐
mon is running on both of them).
domlaunchsecinfo
Syntax:
domlaunchsecinfo domain
Returns 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 launchSecu‐
rity 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 de‐
stroyed.
--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 hy‐
pervisor.
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 required
• minor_fault - The number of other page faults
• unused - 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 domain
• hugetlb_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 op‐
tion in order to set the collection period for the balloon driver. If --live is spec‐
ified, only the running guest collection period is affected. If --config is speci‐
fied, 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-uuid
Convert 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 state
• disk - equivalent of S4 ACPI state
• hybrid - RAM is saved to disk but not powered off
The --duration argument specifies number of seconds before the domain is woken up af‐
ter 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 domain
Wakeup 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-name
Rename 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] [--vm]
[[--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, --vm.
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 enum
• state.reason - reason for entering given state, returned as int from virDomain*Rea‐
son enum corresponding to given state
--cpu-total returns:
• cpu.time - total cpu time spent for this domain in nanoseconds
• cpu.user - user cpu time spent in nanoseconds
• cpu.system - system cpu time spent in nanoseconds
• cpu.haltpoll.success.time - cpu halt polling success time spent in nanoseconds
• cpu.haltpoll.fail.time - cpu halt polling fail time spent in nanoseconds
• cpu.cache.monitor.count - the number of cache monitors for this domain
• cpu.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 used
• balloon.maximum - the maximum memory in KiB allowed
• balloon.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 required
• balloon.minor_fault - the number of other page faults
• balloon.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 in‐
side the domain via virtio balloon
• balloon.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 CPUs
• vcpu.maximum - maximum number of online virtual CPUs
• vcpu.<num>.state - state of the virtual CPU <num>, as number from virVcpuState enum
• vcpu.<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 pro‐
cessor 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.
This group of statistics also reports additional hypervisor-originating per-vCPU
stats. The hypervisor-specific statistics in this group have the following naming
scheme:
vcpu.<num>.$NAME.$TYPE
$NAME name of the statistics field provided by the hypervisor
$TYPE Type of the value. The following types are returned:
cur current instant value
sum aggregate value
max peak value
The returned value may be either an unsigned long long or a boolean. Meaning is
hypervisor specific. Please see the disclaimer for the --vm group which also con‐
sists of hypervisor-specific stats.
--interface returns:
• net.count - number of network interfaces on this domain
• net.<num>.name - name of the interface <num>
• net.<num>.rx.bytes - number of bytes received
• net.<num>.rx.pkts - number of packets received
• net.<num>.rx.errs - number of receive errors
• net.<num>.rx.drop - number of receive packets dropped
• net.<num>.tx.bytes - number of bytes transmitted
• net.<num>.tx.pkts - number of packets transmitted
• net.<num>.tx.errs - number of transmission errors
• net.<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 used
• perf.mbmt - total system bandwidth from one level of cache
• perf.mbml - bandwidth of memory traffic for a memory controller
• perf.cpu_cycles - the count of cpu cycles (total/elapsed)
• perf.instructions - the count of instructions
• perf.cache_references - the count of cache hits
• perf.cache_misses - the count of caches misses
• perf.branch_instructions - the count of branch instructions
• perf.branch_misses - the count of branch misses
• perf.bus_cycles - the count of bus cycles
• perf.stalled_cycles_frontend - the count of stalled frontend cpu cycles
• perf.stalled_cycles_backend - the count of stalled backend cpu cycles
• perf.ref_cpu_cycles - the count of ref cpu cycles
• perf.cpu_clock - the count of cpu clock time
• perf.task_clock - the count of task clock time
• perf.page_faults - the count of page faults
• perf.context_switches - the count of context switches
• perf.cpu_migrations - the count of cpu migrations
• perf.page_faults_min - the count of minor page faults
• perf.page_faults_maj - the count of major page faults
• perf.alignment_faults - the count of alignment faults
• perf.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 listed
• block.<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 <backing‐
Store> index listed in domain XML for backing files
• block.<num>.path - file source of block device <num>, if it is a local file or
block device
• block.<num>.rd.reqs - number of read requests
• block.<num>.rd.bytes - number of read bytes
• block.<num>.rd.times - total time (ns) spent on reads
• block.<num>.wr.reqs - number of write requests
• block.<num>.wr.bytes - number of written bytes
• block.<num>.wr.times - total time (ns) spent on writes
• block.<num>.fl.reqs - total flush requests
• block.<num>.fl.times - total time (ns) spent on cache flushing
• block.<num>.errors - Xen only: the 'oo_req' value
• block.<num>.allocation - offset of highest written sector in bytes
• block.<num>.capacity - logical size of source file in bytes
• block.<num>.physical - physical size of source file in bytes
• block.<num>.threshold - threshold (in bytes) for delivering the VIR_DO‐
MAIN_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 fail‐
ing 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 list
as 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
domain
• memory.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 memory
controller 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 con‐
troller.
--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.
• dirtyrate.calc_mode - the calculation mode used last measurement (page-sam‐
pling/dirty-bitmap/dirty-ring)
• dirtyrate.vcpu.<num>.megabytes_per_second - the calculated memory dirty rate for a
virtual cpu in MiB/s
--vm returns:
The --vm option enables reporting of hypervisor-specific statistics. Naming and mean‐
ing of the fields is entirely hypervisor dependent.
The statistics in this group have the following naming scheme:
vm.$NAME.$TYPE
$NAME name of the statistics field provided by the hypervisor
$TYPE Type of the value. The following types are returned:
cur current instant value
sum aggregate value
max peak value
The returned value may be either an unsigned long long or a boolean.
WARNING: The stats reported in this group are runtime-collected and hypervisor
originated, thus fall outside of the usual stable API policies of libvirt.
Libvirt can't guarantee that the statistics reported from the outside source will
be present in further versions of the hypervisor, or that naming or meaning will
stay consistent. Changes to existing fields, however, are expected to be rare.
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 deliv‐
ering stats. Using --nowait suppresses this behaviour. On the other hand some statis‐
tics 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 mod‐
ifies 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-id
Convert a domain name or id to domain UUID
domxml-from-native
Syntax:
domxml-from-native format config
Convert 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-na‐
tive.
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 do‐
main 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 --by‐
pass-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 SIG‐
INT (usually with Ctrl-C) to the virsh process running dump command. --verbose dis‐
plays 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 re‐
quired in order to produce valid ELF file which can be later processed by the crash
utility.
dumpxml
Syntax:
dumpxml [--inactive] [--security-info] [--update-cpu] [--migratable]
[--xpath EXPRESSION] [--wrap] domain
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 do‐
main 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.
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
edit
Syntax:
edit domain
Edit 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.xml
except 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 ei‐
ther --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 user
Print 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 com‐
mands 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 domain
• user.<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 system
• os.name - the name of the operating system
• os.pretty-name - a pretty name for the operating system
• os.version - the version of the operating system
• os.version-id - the version id of the operating system
• os.kernel-release - the release of the operating system kernel
• os.kernel-version - the version of the operating system kernel
• os.machine - the machine hardware name
• os.variant - a specific variant or edition of the operating system
• os.variant-id - the id for a specific variant or edition of the operating system
--timezone returns:
• timezone.name - the name of the timezone
• timezone.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 domain
• fs.<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 domain
• disk.<num>.name - device node (Linux) or device UNC (Windows)
• disk.<num>.partition - whether this is a partition or disk
• disk.<num>.dependency.count - the number of device dependencies
• disk.<num>.dependency.<num>.name - a dependency name
• disk.<num>.serial - optional disk serial number
• disk.<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 de‐
sired 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] [--thread-pool-min value]
[--thread-pool-max value]]
[[--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 dy‐
namic 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.
The --thread-pool-min and --thread-pool-max options then set lower and upper bound,
respectively of number of threads in worker pool of given iothread. For changes to an
inactive configuration -1 can be specified to remove corresponding boundary from the
domain configuration. For changes to a running guest it's recommended to set the up‐
per boundary first (--thread-pool-max) and only after that set the lower boundary
(--thread-pool-min). It is allowed for the lower boundary to be the same as the upper
boundary, however it's not allowed for the upper boundary to be value of zero.
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 SIG‐
INT (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 argu‐
ment 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 ei‐
ther the --running or --paused flag will allow overriding which state the start
should use.
managedsave-dumpxml
Syntax:
managedsave-dumpxml [--security-info] [--xpath EXPRESSION] [--wrap] domain
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 secu‐
rity sensitive information.
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
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 ei‐
ther 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-xml
except 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 domain
Remove the managedsave state file for a domain, if it exists. This ensures the do‐
main 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 connec‐
tion. If provided, the type parameter must be a valid type attribute for the <do‐
main> 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 pa‐
rameter 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 ei‐
ther --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 over‐
head 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 def‐
initions of the domain. If both --live and --config are specified, the --config op‐
tion takes precedence on getting the current description and both live configuration
and config are updated while setting the description. --current is exclusive and im‐
plied 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] [--postcopy-resume] [--zerocopy]
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] [--comp-zlib-level] [--comp-zstd-level]
[--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 des‐
tination 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 unde‐
fines 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 im‐
ages have to exist on destination host, the --copy-storage-... options only tell lib‐
virt 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-synchro‐
nous-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 migra‐
tion 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) hap‐
pens 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 --post‐
copy-bandwidth. The maximum bandwidth consumed during the pre-copy phase may be lim‐
ited using --bandwidth. In case connection between the hosts breaks while migration
is in post-copy mode, the domain cannot be resumed on either source or destination
host and the migrate command will report an error leaving the domain active on both
hosts. To recover from such situation repeat the original migrate command with an ad‐
ditional --postcopy-resume flag.
--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-con‐
verge-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 maxi‐
mum memory configured for the domain plus any memory consumed by the QEMU process it‐
self. 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.
--zerocopy requests zero-copy mechanism to be used for migrating memory pages. For
QEMU/KVM this means QEMU will be temporarily allowed to lock all guest pages in
host's memory, although only those that are queued for transfer will be locked at the
same time.
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 un‐
safe. 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 usu‐
ally 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 nam‐
ing 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 speci‐
fied, 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", "xbzrle", "zlib", and "zstd". The sup‐
ported set of methods and their combinations depend on a hypervisor and migration op‐
tions. QEMU only supports "zlib" and "zstd" methods when --parallel is used and they
cannot be used at once. When no methods are specified, a hypervisor default methods
will be used. QEMU defaults to "xbzrle" as long as --parallel is not used. For
--parallel migrations QEMU does not provide any default compression method and thus
it has to be specified explicitly using --comp-method. Compression methods can be
tuned further. --comp-mt-level sets compression level for "mt" method. 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. --comp-zlib-level sets the compression level when using
"zlib" method. Values are in range from 0 to 9 and defaults to 1, where 0 is no com‐
pression, 1 is maximum speed and 9 is maximum compression. --comp-zstd-level sets the
compression level when using "zstd" method. Values are in range from 0 to 20 and de‐
faults to 1, where 0 is no compression, 1 is maximum speed and 20 is maximum compres‐
sion.
Providing --tls causes the migration to use the host configured TLS setup (see mi‐
grate_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 ver‐
ification 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 connec‐
tions. The number of such connections can be set using --parallel-connections. Paral‐
lel 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 automati‐
cally determined for managed migration.
Note: The desturi parameter for normal migration and peer2peer migration has differ‐
ent 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/socket
When 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 con‐
figured 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 inter‐
faces, it might be desirable for the migration data stream to be sent over a spe‐
cific interface for either security or performance reasons. In this case migra‐
teuri should be explicitly specified, using an IP address associated with the net‐
work to be used.
• The firewall restricts what ports are available. When libvirt generates a migra‐
tion URI, it will pick a port number using hypervisor specific rules. Some hyper‐
visors 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 lo‐
cal 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/socket
See https://libvirt.org/migration.html#uris for more details on migration URIs.
Optional graphicsuri overrides connection parameters used for automatically recon‐
necting 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 con‐
nect 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 spe‐
cific parameters separated by '&'. Currently recognized parameters are "tlsPort" and
"tlsSubject". For example,
spice://target.host.com:1234/?tlsPort=4567
Optional 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 rep‐
resentation 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 trans‐
ferred 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 compres‐
sion cache misses obtained from domjobinfo.
migrate-getmaxdowntime
Syntax:
migrate-getmaxdowntime domain
Get the maximum tolerable downtime for a domain which is being live-migrated to an‐
other 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 domain
Switch 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 downtime
Set 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 hy‐
pervisor. 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 do‐
main 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 immedi‐
ately. 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 in‐
stance, 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 com‐
bined 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 in‐
structions in order to get a cycles per instruction.
• branch_instructions - Provides the count of branch instructions executed by appli‐
cations running on the platform.
• branch_misses - Provides the count of branch misses executed by applications run‐
ning 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 fre‐
quency 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 ei‐
ther --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 in‐
cludes 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 domain
Reset 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, al‐
though 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 do‐
main XML. For example, it can be used to account for file naming differences in un‐
derlying 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-ini‐
tialized from its pristine template.
Note: To avoid corrupting file system contents within the domain, you should not re‐
use the saved state file for a second restore unless you have also reverted all stor‐
age volumes back to the same contents as when the state file was created.
resume
Syntax:
resume domain
Moves 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 re‐
store 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 SIG‐
INT (usually with Ctrl-C) to the virsh process running save command. --verbose dis‐
plays 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 time‐
outs 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 do‐
main 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 cre‐
ation 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 com‐
mand. 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 [--security-info] [--xpath EXPRESSION] [--wrap] file
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 sen‐
sitive information.
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
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-xml
except 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] domain
Allows you to show (and set) the domain scheduler parameters. The parameters avail‐
able 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, em‐
ulator_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 with cgroups v1,
1-10000 with cgroups v2.
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 io‐
thread_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. Option‐
ally, if the hypervisor supports more displays for a domain, screenID allows specify‐
ing 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 graph‐
ics 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 code‐
set 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.
• linux
The 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)
• xt
The numeric values are those defined by the original XT keyboard controller. No
symbolic names are provided
See virkeycode-xt(7)
• atset1
The numeric values are those defined by the AT keyboard controller, set 1 (aka XT
compatible set). Extended keycoes from atset1 may differ from extended keycodes in
the xt codeset. No symbolic names are provided
See virkeycode-atset1(7)
• atset2
The numeric values are those defined by the AT keyboard controller, set 2. No sym‐
bolic names are provided
See virkeycode-atset2(7)
• atset3
The 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_x
The 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_kbd
The 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 key‐
codes. No symbolic names are provided.
See virkeycode-xtkbd(7)
• win32
The 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)
• usb
The numeric values are those defined by the USB HID specification for keyboard in‐
put. No symbolic names are provided
See virkeycode-usb(7)
• qnum
The numeric values are those defined by the QNUM extension for sending raw key‐
codes. 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 0xf
send-process-signal
Syntax:
send-process-signal domain-id pid signame
Send 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_HUP
set-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 "de‐
stroy", "restart", "rename-restart", "preserve". For type "crash", additional ac‐
tions "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 be‐
fore 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 speci‐
fied, 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 per‐
formed 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 avail‐
able as a deprecated synonym) . Libvirt rounds up to the nearest kibibyte. Some hy‐
pervisors 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 avail‐
able as a deprecated synonym) . Libvirt rounds up to the nearest kibibyte. Some hy‐
pervisors 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 paravir‐
tualized 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 con‐
tainer, 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 origi‐
nal 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 sup‐
ported by the hypervisor. If this command is run before the guest has finished boot‐
ing, 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 ac‐
tive. 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 speci‐
fied 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 snap‐
shot-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 in‐
cludes 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 run‐
ning. If --console is requested, attach to the console after creation. If --autode‐
stroy 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 de‐
scriptors 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-ini‐
tialized from its pristine template.
suspend
Syntax:
suspend domain
Suspend a running domain. It is kept in memory but won't be scheduled anymore.
ttyconsole
Syntax:
ttyconsole domain
Output 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]
[--tpm] [--keep-tpm]
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 do‐
main is active, this flag is ignored.
The --checkpoints-metadata flag guarantees that any checkpoints (see the check‐
point-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 (/do‐
main/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 vol‐
ume target names or source paths of storage volumes to be removed along with the un‐
defined 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. Note that this also removes only the top level image of a
backing chain, any backing stores of the image are kept as they may be shared. (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 as if they were specified via --storage.
The --delete-storage-volume-snapshots (previously --delete-snapshots) flag specifies
that any snapshots associated with the storage volume should be deleted as well. Re‐
quires 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 re‐
moval.
--tpm and --keep-tpm specify accordingly to delete or keep a TPM's persistent state
directory structure and files. If the flags are omitted then the persistent_state at‐
tribute in the TPM emulator definition in the domain XML determines whether the TPM
state is kept.
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 lim‐
ited 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: yyyy
STATES
The State field displays the current operating state of a virtual CPU
• offline
The virtual CPU is offline and not usable by the domain. This state is not sup‐
ported by all hypervisors.
• running
The virtual CPU is available to the domain and is operating.
• blocked
The 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 state
The virtual CPU state could not be determined. This could happen if the hypervisor
is newer than virsh.
• N/A
There'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 physi‐
cal 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 domain
Output 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 de‐
vice 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 un‐
less --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 speci‐
fies 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 vir‐
tual 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 (block|file|network) cache
can be one of "default", "none", "writethrough", "writeback", "directsync" or "un‐
safe". 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:con‐
troller.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. multi‐
function 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 net‐
work disk or host information. Host information can be provided using the tags
--source-host-name, --source-host-transport, and --source-host-socket, which respec‐
tively 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:bus:slot.func‐
tion.
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 op‐
tional, so "average,peak", "average,,burst", "average,,,floor", "average" and
",,,floor" are also legal. Values for average, floor and peak are expressed in kilo‐
bytes 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#quality-of-service.
--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 cur‐
rent 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 auto‐
matically.
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 defini‐
tion 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 un‐
plug 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 al‐
low 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 ar‐
rive 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]] [--print-xml]
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.
If --print-xml is specified, then the XML used to detach the interface is printed in‐
stead.
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 documen‐
tation at https://libvirt.org/formatdomain.html#elementsDevices to learn about lib‐
virt 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='me‐
dia'>), 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, al‐
ter persistent configuration, effect observed on next startup of the guest. --cur‐
rent can be either or both of live and config, depends on the hypervisor's implemen‐
tation. 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 chang‐
ing the media.
dom-fd-associate
Syntax:
dom-fd-associate domain --name FDGROUPNAME --pass-fds M,N,....
[--seclabel-writable] [--seclabel-restore]
Associate one or more fds described via --pass-fds argument to domain as --name. The
lifetime of the passed fd group is the same as the connection, thus exiting virsh
un-registers them afterwards.
By default security labels are applied if needed but they are not restored after use
to avoid keeping them open unnecessarily. Best-effort security label restore may be
requested by using the --seclabel-restore flag.
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 de‐
vice key is generally specified by the bus name followed by its address, using under‐
scores 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 FILE [--validate]
Create a device on the host node that can then be assigned to virtual machines. Nor‐
mally, 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.
If --validate is specified, validates the format of the XML document against an in‐
ternal RNG schema.
nodedev-destroy
Syntax:
nodedev-destroy device
Destroy (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 FILE [--validate]
Define an inactive persistent device or modify an existing persistent one from the
XML FILE.
If --validate is specified, validates the format of the XML document against an in‐
ternal RNG schema.
nodedev-undefine
Syntax:
nodedev-undefine device
Undefine the configuration for a persistent device. If the device is active, make it
transient.
nodedev-start
Syntax:
nodedev-start device
Start a (previously defined) inactive device.
nodedev-detach
Syntax:
nodedev-detach nodedev [--driver backend_driver]
Detach nodedev from the host driver and bind it to a special driver that provides the
API needed by the hypervisor for assigning the device to a virtual machine (using
<hostdev> in the domain XML definition). This is reversed with nodedev-reattach, and
is done automatically by the hypervisor driver for managed devices (those devices
with "managed='yes'" in their XML definition).
Different hypervisors expect the device being assigned to be bound to different driv‐
ers. For example, QEMU's "vfio" backend requires the device to be bound to the driver
"vfio-pci" or to a "VFIO variant" driver (this is a driver that supports the full API
provided by vfio-pci, plus some other APIs to support things like live migration).
The --driver parameter can be used to specify a particular driver (e.g. a device-spe‐
cific VFIO variant driver) the device should be bound to. When --driver is omitted,
the default driver for the hypervisor is used ("vfio-pci" for QEMU, "pciback" for
Xen).
nodedev-dumpxml
Syntax:
nodedev-dumpxml [--xpath EXPRESSION] [--wrap] device
Dump a <device> XML representation for the given node device, including such informa‐
tion 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).
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
nodedev-info
Syntax:
nodedev-info device
Returns 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 nodedev
Declare 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 nodedev
Trigger a device reset for nodedev, useful prior to transferring a node device be‐
tween 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] device
Configure 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 vir‐
tual 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 op‐
tion 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-desc
Syntax:
net-desc network [[--live] [--config] |
[--current]] [--title] [--edit] [--new-desc
New description or title message]
Show or modify description and title of a network. These values are user fields that
allow storing arbitrary textual data to allow easy identification of networks. Title
should be short, although it's not enforced. (See also net-metadata that works with
XML based network metadata.)
Flags --live or --config select whether this command works on live or persistent def‐
initions of the network. If both --live and --config are specified, the --config op‐
tion takes precedence on getting the current description and both live configuration
and config are updated while setting the description. --current is exclusive and im‐
plied if none of these was specified.
Flag --edit specifies that an editor with the contents of current description or ti‐
tle 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 dis‐
played instead of being modified.
net-destroy
Syntax:
net-destroy network
Destroy (stop) a given transient or persistent virtual network specified by its name
or UUID. This takes effect immediately.
net-dumpxml
Syntax:
net-dumpxml [--inactive] [--xpath EXPRESSION] [--wrap] network
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.
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
net-edit
Syntax:
net-edit network
Edit 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.xml
except 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 network
Returns basic information about the network object.
net-list
Syntax:
net-list [--inactive | --all]
{ [--table] | --name | --uuid }
[--persistent] [<--transient>]
[--autostart] [<--no-autostart>]
[--title]
Returns the list of active networks, if --all is specified this will also include de‐
fined 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 dis‐
abled.
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.
If --title is specified, then the short network description (title) is printed in an
extra column. This flag is usable only with the default --table output.
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-metadata
Syntax:
net-metadata network [[--live] [--config] | [--current]]
[--edit] [uri] [key] [set] [--remove]
Show or modify custom XML metadata of a network. The metadata is a user defined XML
that allows storing arbitrary XML data in the network definition. Multiple separate
custom metadata pieces can be stored in the network XML. The pieces are identified
by a private XML namespace provided via the uri argument. (See also net-desc that
works with textual metadata of a network, such as title and description.)
Flags --live or --config select whether this command works on live or persistent def‐
initions of the network. If both --live and --config are specified, the --config op‐
tion takes precedence on getting the current description and both live configuration
and config are updated while setting the description. --current is exclusive and im‐
plied 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.
net-name
Syntax:
net-name network-UUID
Convert a network UUID to network name.
net-start
Syntax:
net-start network
Start a (previously defined) inactive network.
net-undefine
Syntax:
net-undefine network
Undefine the configuration for a persistent network. If the network is active, make
it transient.
net-uuid
Syntax:
net-uuid network-name
Convert 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 option‐
ally 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", "for‐
ward", "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 re‐
quested 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 equiva‐
lent 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 } network
List 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. Op‐
tionally, the format of the input XML file can be validated against an internal RNG
schema with --validate.
net-port-dumpxml
Syntax:
net-port-dumpxml [--xpath EXPRESSION] [--wrap] network port
Output the network port information as an XML dump to stdout.
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
net-port-delete
Syntax:
net-port-delete network port
Delete 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 in‐
teger 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 persis‐
tent one from the XML file. Optionally, the format of the input XML file can be vali‐
dated against an internal RNG schema with --validate.
iface-destroy
Syntax:
iface-destroy interface
Destroy (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 [--inactive] [--xpath EXPRESSION] [--wrap] interface
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.
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
iface-edit
Syntax:
iface-edit interface
Edit 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.xml
except 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 in‐
clude defined but inactive interfaces. If --inactive is specified only the inactive
ones will be listed.
iface-name
Syntax:
iface-name interface
Convert 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 interface
Convert a host interface name to MAC address.
interface specifies the interface name.
iface-start
Syntax:
iface-start interface
Start 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 interface
Undefine the configuration for an inactive host interface.
iface-begin
Syntax:
iface-begin
Create 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. Unde‐
fined 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 roll‐
back.
iface-commit
Syntax:
iface-commit
Declare 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-rollback
Revert all host interface settings back to the state recorded in the last iface-be‐
gin. 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 for‐
mats, 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 fol‐
lowing 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> ele‐
ment 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 ele‐
ments in srcSpec.
For a "logical" pool, the contents of the srcSpec file are ignored, although if pro‐
vided 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 argu‐
ments. 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 tar‐
get device if not. If --overwrite is specified, mkfs is always executed and any ex‐
isting 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 speci‐
fied, 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 speci‐
fied.
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 parti‐
tions 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 pro‐
vided, 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 spec‐
ified, 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 directo‐
ries (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-par‐
ent-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 pro‐
vided, then pool-build is called with no flags.
For a "logical" pool only [--name] needs to be provided. The [--source-name] if pro‐
vided 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. Oth‐
erwise, 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-uuid
Destroy (stop) a given pool object. Libvirt will no longer manage the storage de‐
scribed 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-uuid
Destroy 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] [--xpath EXPRESSION] [--wrap] pool-or-uuid
Returns 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 cur‐
rent pool configuration.
If the --xpath argument provides an XPath expression, it will be evaluated against
the output XML and only those matching nodes will be printed. The default behaviour
is to print each matching node as a standalone document, however, for ease of addi‐
tional processing, the --wrap argument will cause the matching node to be wrapped in
a common root node.
pool-edit
Syntax:
pool-edit pool-or-uuid
Edit 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.xml
except 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-uuid
Returns 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; --in‐
active 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 ex‐
clusive 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', 'glus‐
ter', 'zfs', 'vstorage' and 'iscsi-direct'.
The --details option instructs virsh to additionally display pool persistence and ca‐
pacity 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 uuid
Convert the uuid to a pool name.
pool-refresh
Syntax:
pool-refresh pool-or-uuid
Refresh 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-overwr
腾讯云面向开发者汇聚海量精品云计算使用和开发经验，营造开放的云计算技术生态圈。
更多推荐
6
0- 0
已为社区贡献9条内容
所有评论(0)