Sys::Virt::Domain(3pm)

NAME

Sys::Virt::Domain - Represent & manage a libvirt guest domain

DESCRIPTION

The "Sys::Virt::Domain" module represents a guest domain managed by the virtual machine monitor.

METHODS

my $id = $dom->get_id(): Returns an integer with a locally unique identifier for the domain.
my $uuid = $dom->get_uuid(): Returns a 16 byte long string containing the raw globally unique
identifier (UUID) for the domain.
my $uuid = $dom->get_uuid_string(): Returns a printable string representation of the raw UUID, in the
format 'XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX'.
my $name = $dom->get_name(): Returns a string with a locally unique name of the domain
$dom->is_active(): Returns a true value if the domain is currently running
$dom->is_persistent(): Returns a true value if the domain has a persistent configuration
file defined
my $xml = $dom->get_xml_description(): Returns an XML document containing a complete description of the
domain's configuration
my $type = $dom->get_os_type(): Returns a string containing the name of the OS type running within the domain.
$dom->create(): Start a domain whose configuration was previously defined using the "define_domain" method in Sys::Virt.
$dom->undefine(): Remove the configuration associated with a domain previously
defined with the "define_domain" method in Sys::Virt. If the domain is running, you probably want to use the "shutdown" or "destroy"
methods instead.
$dom->suspend(): Temporarily stop execution of the domain, allowing later
continuation by calling the "resume" method.
$dom->resume(): Resume execution of a domain previously halted with the "suspend"
method.
$dom->save($filename): Take a snapshot of the domain's state and save the information to
the file named in the $filename parameter. The domain can later be restored from this file with the "restore_domain" method on the
Sys::Virt object.
$dom->managed_save($flags=0): Take a snapshot of the domain's state and save the information to a managed save location. The domain will be automatically restored
with this state when it is next started. The $flags parameter is
unused and defaults to zero.
$bool = $dom->has_managed_save_image($flags=0): Return a non-zero value if the domain has a managed save image that will be used at next start. The $flags parameter is unused and
defaults to zero.
$dom->managed_save_remove($flags=0): Remove the current managed save image, causing the guest to perform a full boot next time it is started. The $flags parameter is unused and defaults to zero.
$dom->core_dump($filename[, $flags]): Trigger a core dump of the guest virtual machine, saving its memory image to $filename so it can be analysed by tools such as "crash". The optional $flags flags parameter is currently unused and if
omitted will default to 0.
$dom->destroy(): Immediately terminate the machine, and remove it from the virtual
machine monitor. The $dom handle is invalid after this call
completes and should not be used again.
my $info = $dom->get_info(): Returns a hash reference summarising the execution state of the
domain. The elements of the hash are as follows:; maxMem
The maximum memory allowed for this domain, in kilobytes; memory
The current memory allocated to the domain in kilobytes; cpuTime
The amount of CPU time used by the domain; nrVirtCpu
The current number of virtual CPUs enabled in the domain; state
The execution state of the machine, which will be one of the
constants &Sys::Virt::Domain::STATE_*.
my $info = $dom->get_block_info($dev, $flags=0): Returns a hash reference summarising the disk usage of the host
backing store for a guest block device. The $dev parameter should
be the path to the backing store on the host. $flags is currently
unused and defaults to 0 if omitted. The returned hash contains the following elements; capacity
Logical size in bytes of the block device backing image *; allocation
Highest allocated extent in bytes of the block device backing
image; physical
Physical size in bytes of the container of the backing image
$dom->set_max_memory($mem): Set the maximum memory for the domain to the value $mem. The value of the $mem parameter is specified in kilobytes.
$mem = $dom->get_max_memory(): Returns the current maximum memory allowed for this domain in
kilobytes.
$dom->set_memory($mem): Set the current memory for the domain to the value $mem. The value of the $mem parameter is specified in kilobytes. This must be less than, or equal to the domain's max memory limit.
$dom->shutdown(): Request that the guest OS perform a graceful shutdown and poweroff.
$dom->reboot([$flags]): Request that the guest OS perform a graceful shutdown and
optionally restart. The optional $flags parameter is currently
unused and if omitted defaults to zero.
$dom->get_max_vcpus(): Return the maximum number of vcpus that are configured for the
domain
$dom->attach_device($xml[, $flags]): Hotplug a new device whose configuration is given by $xml, to the
running guest. The optional <$flags> parameter defaults to 0, but
can accept one of the device hotplug flags described later.
$dom->detach_device($xml[, $flags]): Hotunplug a existing device whose configuration is given by $xml,
from the running guest. The optional <$flags> parameter defaults to 0, but can accept one of the device hotplug flags described later.
$dom->update_device($xml[, $flags]): Update the configuration of an existing device. The new
configuration is given by $xml. The optional <$flags> parameter
defaults to 0 but can accept one of the device hotplug flags
described later.
$data = $dom->block_peek($path, $offset, $size[, $flags): Peek into the guest disk $path, at byte $offset capturing $size
bytes of data. The returned scalar may contain embedded NULLs. The optional $flags parameter is currently unused and if omitted
defaults to zero.
$data = $dom->memory_peek($offset, $size[, $flags]): Peek into the guest memory at byte $offset virtual address,
capturing $size bytes of memory. The return scalar may contain
embedded NULLs. The optional $flags parameter is currently unused
and if omitted defaults to zero.
$flag = $dom->get_autostart();: Return a true value if the guest domain is configured to
automatically start upon boot. Return false, otherwise
$dom->set_autostart($flag): Set the state of the autostart flag, which determines whether the
guest will automatically start upon boot of the host OS
$dom->set_vcpus($count): Set the number of virtual CPUs in the guest VM to $count
$type = $dom->get_scheduler_type(): Return the scheduler type for the guest domain
%stats = $dom->block_stats($path): Fetch the current I/O statistics for the block device given by
$path. The returned hash containins keys for
my %params = $dom->get_scheduler_parameters(): Return the set of scheduler tunable parameters for the guest.
$dom->set_scheduler_parameters($params): Update the set of scheduler tunable parameters. The value names for tunables vary, and can be discovered using the
"get_scheduler_params" call; "rd_req"
Number of read requests; "rd_bytes"
Number of bytes read; "wr_req"
Number of write requests; "wr_bytes"
Number of bytes written; "errs"
Some kind of error count
$dom->interface_stats($path): Fetch the current I/O statistics for the block device given by
$path. The returned hash containins keys for; "rx_bytes"
Total bytes received; "rx_packets"
Total packets received; "rx_errs"
Total packets received with errors; "rx_drop"
Total packets drop at reception; "tx_bytes"
Total bytes transmitted; "tx_packets"
Total packets transmitted; "tx_errs"
Total packets transmitted with errors; "tx_drop"
Total packets dropped at transmission.
$dom->memory_stats($flags=0): Fetch the current memory statistics for the guest domain. The
$flags parameter is currently unused and can be omitted. The
returned hash containins keys for; "swap_in"
Data read from swap space; "swap_out"
Data written to swap space; "major_fault"
Page fault involving disk I/O; "minor_fault"
Page fault not involving disk I/O; "unused"
Memory not used by the system; "available"
Total memory seen by guest
%info = $dom->get_security_label(): Fetch information about the security label assigned to the guest
domain. The returned hash has two keys, "model" gives the name of
the security model in effect (eg "selinux"), while "label" provides the name of the security label applied to the domain.
$ddom = $dom->migrate(destcon, flags, dname, uri, bandwidth): Migrate a domain to an alternative host. The "destcon" parameter
should be a "Sys::Virt" connection to the remote target host. If
the "flags" parameter is zero offline migration will be performed. The "Sys::Virt::Domain::MIGRATE_LIVE" constant can be used to
request live migration. The "dname" parameter allows the guest to
be renamed on the target host, if set to "undef", the domains'
current name will be maintained. In normal circumstances, the
source host determines the target hostname from the URI associated with the "destcon" connection. If the destination host is multihomed it may be necessary to supply an alternate destination
hostame via the "uri" parameter. The "bandwidth" parameter allows
network usage to be throttled during migration. If set to zero, no throttling will be performed. The "flags", "dname", "uri" and
"bandwidth" parameters are all optional, and if omitted default to zero, "undef", "undef", and zero respectively.
$dom->migrate_to_uri(desturi, flags, dname, uri, bandwidth): Migrate a domain to an alternative host. The "destri" parameter
should be a valid libvirt connection URI for the remote target
host. If the "flags" parameter is zero offline migration will be
performed. The "Sys::Virt::Domain::MIGRATE_LIVE" constant can be
used to request live migration. The "dname" parameter allows the
guest to be renamed on the target host, if set to "undef", the
domains' current name will be maintained. In normal circumstances, the source host determines the target hostname from the URI
associated with the "destcon" connection. If the destination host
is multi-homed it may be necessary to supply an alternate
destination hostame via the "uri" parameter. The "bandwidth"
parameter allows network usage to be throttled during migration. If set to zero, no throttling will be performed. The "flags", "dname", "uri" and "bandwidth" parameters are all optional, and if omitted
default to zero, "undef", "undef", and zero respectively.
$dom->migrate_set_max_downtime($downtime, $flags): Set the maximum allowed downtime during migration of the guest. A
longer downtime makes it more likely that migration will complete, at the cost of longer time blackout for the guest OS at the switch over point. The "downtime" parameter is measured in milliseconds.
The $flags parameter is currently unused and defaults to zero.
@vcpuinfo = $dom->get_vcpu_info(): Obtain information about the state of all virtual CPUs in a running guest domain. The returned list will have one element for each
vCPU, where each elements contains a hash reference. The keys in
the hash are, "number" the vCPU number, "cpu" the physical CPU on
which the vCPU is currently scheduled, "cpuTime" the cummulative
execution time of the vCPU, "state" the running state and
"affinity" giving the allowed shedular placement. The value for
"affinity" is a string representing a bitmask against physical
CPUs, 8 cpus per character.
$dom->pin_vcpu($vcpu, $mask): Ping the virtual CPU given by index $vcpu to physical CPUs given by $mask. The $mask is a string representing a bitmask against
physical CPUs, 8 cpus per character.
my $info = $dom->get_job_info(): Returns a hash reference summarising the execution state of the
background job. The elements of the hash are as follows:
$dom->abort_job(): Aborts the currently executing job
$count = $dom->num_of_snapshots(): Return the number of saved snapshots of the domain
@names = $dom->list_snapshot_names(): List the names of all saved snapshots. The names can be used with
the "lookup_snapshot_by_name"
@snapshots = $dom->list_snapshots(): Return a list of all snapshots currently known to the domain. The
elements in the returned list are instances of the
Sys::Virt::DomainSnapshot class.
$dom->has_current_snapshot(): Returns a true value if the domain has a currently active snapshot
$snapshot = $dom->current_snapshot(): Returns the currently active snapshot for the domain.; type
The type of job, one of the JOB TYPE constants listed later in this document.; timeElapsed
The elapsed time in milliseconds; timeRemaining
The expected remaining time in milliseconds. Only set if the
"type" is JOB_UNBOUNDED.; dataTotal
The total amount of data expected to be processed by the job,
in bytes.; dataProcessed
The current amount of data processed by the job, in bytes.; dataRemaining
The expected amount of data remaining to be processed by the
job, in bytes.; memTotal
The total amount of mem expected to be processed by the job, in bytes.; memProcessed
The current amount of mem processed by the job, in bytes.; memRemaining
The expected amount of mem remaining to be processed by the
job, in bytes.; fileTotal
The total amount of file expected to be processed by the job,
in bytes.; fileProcessed
The current amount of file processed by the job, in bytes.; fileRemaining
The expected amount of file remaining to be processed by the
job, in bytes.

CONSTANTS

A number of the APIs take a "flags" parameter. In most cases passing a value of zero will be satisfactory. Some APIs, however, accept named
constants to alter their behaviour. This section documents the current known constants.
DOMAIN STATE: The domain state constants are useful in interpreting the "state" key
in the hash returned by the "get_info" method.; Sys::Virt::Domain::STATE_NOSTATE
The domain is active, but is not running / blocked (eg idle); Sys::Virt::Domain::STATE_RUNNING
The domain is active and running; Sys::Virt::Domain::STATE_BLOCKED
The domain is active, but execution is blocked; Sys::Virt::Domain::STATE_PAUSED
The domain is active, but execution has been paused; Sys::Virt::Domain::STATE_SHUTDOWN
The domain is active, but in the shutdown phase; Sys::Virt::Domain::STATE_SHUTOFF
The domain is inactive, and shut down.; Sys::Virt::Domain::STATE_CRASHED
The domain is inactive, and crashed.
MEMORY PEEK: The following constants can be used with the "memory_peek" method's
flags parameter; Sys::Virt::Domain::MEMORY_VIRTUAL
Indicates that the offset is using virtual memory addressing.
VCPU STATE: The following constants are useful when interpreting the virtual CPU
run state; Sys::Virt::Domain::VCPU_OFFLINE
The virtual CPU is not online; Sys::Virt::Domain::VCPU_RUNNING
The virtual CPU is executing code; Sys::Virt::Domain::VCPU_BLOCKED
The virtual CPU is waiting to be scheduled
XML DUMP OPTIONS: The following constants are used to control the information included in the XML configuration dump; Sys::Virt::Domain::XML_INACTIVE
Report the persistent inactive configuration for the guest, even if it is currently running.; Sys::Virt::Domain::XML_SECURE
Include security sensitive information in the XML dump, such as
passwords.
DEVICE HOTPLUG OPTIONS: The following constants are used to control device hotplug operations; Sys::Virt::Domain::DEVICE_MODIFY_CURRENT
Modify the domain in its current state; Sys::Virt::Domain::DEVICE_MODIFY_LIVE
Modify only the live state of the domain; Sys::Virt::Domain::DEVICE_MODIFY_CONFIG
Modify only the persistent config of the domain
MIGRATE OPTIONS: The following constants are used to control how migration is performed; Sys::Virt::Domain::MIGRATE_LIVE
Migrate the guest without interrupting its execution on the source host.; Sys::Virt::Domain::MIGRATE_PEER2PEER
Manage the migration process over a direct peer-2-peer connection
between the source and destination host libvirtd daemons.; Sys::Virt::Domain::MIGRATE_TUNNELLED
Tunnel the migration data over the libvirt daemon connection,
rather than the native hypervisor data transport. Requires
PEER2PEER flag to be set.; Sys::Virt::Domain::MIGRATE_PERSIST_DEST
Make the domain persistent on the destination host, defining its
configuration file upon completion of migration.; Sys::Virt::Domain::MIGRATE_UNDEFINE_SOURCE
Remove the domain's persistent configuration after migration
completes successfully.; Sys::Virt::Domain::MIGRATE_PAUSED
Do not re-start execution of the guest CPUs on the destination host after migration completes.
JOB TYPES: The following constants describe the different background job types.; Sys::Virt::Domain::JOB_NONE
No job is active; Sys::Virt::Domain::JOB_BOUNDED
A job with a finite completion time is active; Sys::Virt::Domain::JOB_UNBOUNDED
A job with an unbounded completion time is active; Sys::Virt::Domain::JOB_COMPLETED
The job has finished, but isn't cleaned up; Sys::Virt::Domain::JOB_FAILED
The job has hit an error, but isn't cleaned up; Sys::Virt::Domain::JOB_CANCELLED
The job was aborted at user request, but isn't cleaned up
STATE CHANGE EVENTS: The following constants allow domain state change events to be
interpreted. The events contain both a state change, and a reason.; Sys::Virt::Domain::EVENT_DEFINED
Indicates that a persistent configuration has been defined for the domain.

Sys::Virt::Domain::EVENT_DEFINED_ADDED
The defined configuration is newly added

Sys::Virt::Domain::EVENT_DEFINED_UPDATED

The defined configuration is an update to an existing
configuration
Sys::Virt::Domain::EVENT_RESUMED: The domain has resumed execution; Sys::Virt::Domain::EVENT_RESUMED_MIGRATED
The domain resumed because migration has completed. This is
emitted on the destination host.; Sys::Virt::Domain::EVENT_RESUMED_UNPAUSED
The domain resumed because the admin unpaused it.
Sys::Virt::Domain::EVENT_STARTED: The domain has started running; Sys::Virt::Domain::EVENT_STARTED_BOOTED
The domain was booted from shutoff state; Sys::Virt::Domain::EVENT_STARTED_MIGRATED
The domain started due to an incoming migration; Sys::Virt::Domain::EVENT_STARTED_RESTORED
The domain was restored from saved state file
Sys::Virt::Domain::EVENT_STOPPED: The domain has stopped running; Sys::Virt::Domain::EVENT_STOPPED_CRASHED
The domain stopped because guest operating system has crashed; Sys::Virt::Domain::EVENT_STOPPED_DESTROYED
The domain stopped because administrator issued a destroy
command.; Sys::Virt::Domain::EVENT_STOPPED_FAILED
The domain stopped because of a fault in the host
virtualization environment.; Sys::Virt::Domain::EVENT_STOPPED_MIGRATED
The domain stopped because it was migrated to another machine.; Sys::Virt::Domain::EVENT_STOPPED_SAVED
The domain was saved to a state file; Sys::Virt::Domain::EVENT_STOPPED_SHUTDOWN
The domain stopped due to graceful shutdown of the guest.
Sys::Virt::Domain::EVENT_SUSPENDED: The domain has stopped executing, but still exists; Sys::Virt::Domain::EVENT_SUSPENDED_MIGRATED
The domain has been suspended due to offline migration; Sys::Virt::Domain::EVENT_SUSPENDED_PAUSED
The domain has been suspended due to administrator pause
request.
Sys::Virt::Domain::EVENT_UNDEFINED: The persistent configuration has gone away; Sys::Virt::Domain::EVENT_UNDEFINED_REMOVED
The domain configuration has gone away due to it being removed by administrator.
EVENT ID CONSTANTS: Sys::Virt::Domain::EVENT_ID_LIFECYCLE
Domain lifecycle events; Sys::Virt::Domain::EVENT_ID_REBOOT
Soft / warm reboot events; Sys::Virt::Domain::EVENT_ID_RTC_CHANGE
RTC clock adjustments; Sys::Virt::Domain::EVENT_ID_IO_ERROR
File IO errors, typically from disks; Sys::Virt::Domain::EVENT_ID_WATCHDOG
Watchdog device triggering; Sys::Virt::Domain::EVENT_ID_GRAPHICS
Graphics client connections.; Sys::Virt::Domain::EVENT_ID_IO_ERROR_REASON
File IO errors, typically from disks, with a root cause
IO ERROR EVENT CONSTANTS: These constants describe what action was taken due to the IO error.; Sys::Virt::Domain::EVENT_IO_ERROR_NONE
No action was taken, the error was ignored & reported as success to guest; Sys::Virt::Domain::EVENT_IO_ERROR_PAUSE
The guest is paused since the error occurred; Sys::Virt::Domain::EVENT_IO_ERROR_REPORT
The error has been reported to the guest OS
WATCHDOG EVENT CONSTANTS: These constants describe what action was taken due to the watchdog
firing; Sys::Virt::Domain::EVENT_WATCHDOG_NONE
No action was taken, the watchdog was ignored; Sys::Virt::Domain::EVENT_WATCHDOG_PAUSE
The guest is paused since the watchdog fired; Sys::Virt::Domain::EVENT_WATCHDOG_POWEROFF
The guest is powered off after the watchdog fired; Sys::Virt::Domain::EVENT_WATCHDOG_RESET
The guest is reset after the watchdog fired; Sys::Virt::Domain::EVENT_WATCHDOG_SHUTDOWN
The guest attempted to gracefully shutdown after the watchdog fired; Sys::Virt::Domain::EVENT_WATCHDOG_DEBUG
No action was taken, the watchdog was logged
GRAPHICS EVENT PHASE CONSTANTS: These constants describe the phase of the graphics connection; Sys::Virt::Domain::EVENT_GRAPHICS_CONNECT
The initial client connection; Sys::Virt::Domain::EVENT_GRAPHICS_INITIALIZE
The client has been authenticated & the connection is running; Sys::Virt::Domain::EVENT_GRAPHICS_DISCONNECT
The client has disconnected
GRAPHICS EVENT ADDRESS CONSTANTS: These constants describe the format of the address; Sys::Virt::Domain::EVENT_GRAPHICS_ADDRESS_IPV4
An IPv4 address; Sys::Virt::Domain::EVENT_GRAPHICS_ADDRESS_IPV6
An IPv6 address

AUTHORS

Daniel P. Berrange <berrange@redhat.com>

COPYRIGHT

LICENSE

This program is free software; you can redistribute it and/or modify it under the terms of either the GNU General Public License as published
by the Free Software Foundation (either version 2 of the License, or at your option any later version), or, the Artistic License, as specified in the Perl README file.

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