org.libvirt

Class Domain

public class Domain extends Object

A virtual machine defined within libvirt.
Field Summary
protected Libvirtlibvirt
The libvirt connection from the hypervisor
Method Summary
intabortJob()
Requests that the current background job be aborted at the soonest opportunity.
voidattachDevice(String xmlDesc)
Creates a virtual device attachment to backend.
voidattachDeviceFlags(String xmlDesc, int flags)
Creates a virtual device attachment to backend.
DomainBlockInfoblockInfo(String path)
This function returns block device (disk) stats for block devices attached to the domain.
DomainBlockStatsblockStats(String path)
Returns block device (disk) stats for block devices attached to this domain.
voidcoreDump(String to, int flags)
Dumps the core of this domain on a given file for analysis.
intcpuMapLength(int maxCpus)
It returns the length (in bytes) required to store the complete CPU map between a single virtual & all physical CPUs of a domain.
intcreate()
Launches this defined domain.
intcreate(int flags)
Launches this defined domain with the provide flags.
voiddestroy()
Destroys this domain object.
voiddetachDevice(String xmlDesc)
Destroys a virtual device attachment to backend.
voiddetachDeviceFlags(String xmlDesc, int flags)
Destroys a virtual device attachment to backend.
intfree()
Frees this domain object.
booleangetAutostart()
Provides a boolean value indicating whether the network is configured to be automatically started when the host machine boots.
ConnectgetConnect()
Provides the connection object associated with a domain.
intgetID()
Gets the hypervisor ID number for the domain
DomainInfogetInfo()
Extract information about a domain.
DomainJobInfogetJobInfo()
Extract information about progress of a background job on a domain.
longgetMaxMemory()
Retrieve the maximum amount of physical memory allocated to a domain.
intgetMaxVcpus()
Provides the maximum number of virtual CPUs supported for the guest VM.
StringgetName()
Gets the public name for this domain
StringgetOSType()
Gets the type of domain operation system.
SchedParameter[]getSchedulerParameters()
Gets the scheduler parameters.
String[]getSchedulerType()
Gets the scheduler type.
int[]getUUID()
Get the UUID for this domain.
StringgetUUIDString()
Gets the UUID for this domain as string.
int[]getVcpusCpuMaps()
Returns the cpumaps for this domain Only the lower 8 bits of each int in the array contain information.
VcpuInfo[]getVcpusInfo()
Extracts information about virtual CPUs of this domain
StringgetXMLDesc(int flags)
Provides an XML description of the domain.
inthasCurrentSnapshot()
Determine if the domain has a snapshot
inthasManagedSaveImage()
Determine if the domain has a managed save image
DomainInterfaceStatsinterfaceStats(String path)
Returns network interface stats for interfaces attached to this domain.
intisActive()
Determine if the domain is currently running
intisPersistent()
Determine if the domain has a persistent configuration which means it will still exist after shutting down
intmanagedSave()
suspend a domain and save its memory contents to a file on disk.
intmanagedSaveRemote()
Remove any managed save images from the domain
MemoryStatistic[]memoryStats(int number)
This function provides memory statistics for the domain.
Domainmigrate(Connect dconn, long flags, String dname, String uri, long bandwidth)
Migrate this domain object from its current host to the destination host given by dconn (a connection to the destination host).
intmigrateSetMaxDowntime(long downtime)
Sets maximum tolerable time for which the domain is allowed to be paused at the end of live migration.
intmigrateToURI(String uri, long flags, String dname, long bandwidth)
Migrate the domain object from its current host to the destination host given by duri.
voidpinVcpu(int vcpu, int[] cpumap)
Dynamically changes the real CPUs which can be allocated to a virtual CPU.
protected voidprocessError()
Error handling logic to throw errors.
voidreboot(int flags)
Reboot this domain, the domain object is still usable there after but the domain OS is being stopped for a restart.
voidresume()
Resume this suspended domain, the process is restarted from the state where it was frozen by calling virSuspendDomain().
intrevertToSnapshot(DomainSnapshot snapshot)
Revert the domain to a given snapshot.
voidsave(String to)
Suspends this domain and saves its memory contents to a file on disk.
voidsetAutostart(boolean autostart)
Configures the network to be automatically started when the host machine boots.
voidsetMaxMemory(long memory)
* Dynamically change the maximum amount of physical memory allocated to a domain.
voidsetMemory(long memory)
Dynamically changes the target amount of physical memory allocated to this domain.
voidsetSchedulerParameters(SchedParameter[] params)
Changes the scheduler parameters
voidsetVcpus(int nvcpus)
Dynamically changes the number of virtual CPUs used by this domain.
voidshutdown()
Shuts down this domain, the domain object is still usable there after but the domain OS is being stopped.
DomainSnapshotsnapshotCreateXML(String xmlDesc)
Creates a new snapshot of a domain based on the snapshot xml contained in xmlDesc.
DomainSnapshotsnapshotCurrent()
Get the current snapshot for a domain, if any.
String[]snapshotListNames()
Collect the list of domain snapshots for the given domain.
DomainSnapshotsnapshotLookupByName(String name)
Retrieve a snapshot by name
intsnapshotNum()
Provides the number of domain snapshots for this domain..
voidsuspend()
Suspends this active domain, the process is frozen without further access to CPU resources and I/O but the memory used by the domain at the hypervisor level will stay allocated.
voidundefine()
undefines this domain but does not stop it if it is running
intupdateDeviceFlags(String xml, int flags)
Change a virtual device on a domain

Field Detail

libvirt

protected Libvirt libvirt
The libvirt connection from the hypervisor

Method Detail

abortJob

public int abortJob()
Requests that the current background job be aborted at the soonest opportunity. This will block until the job has either completed, or aborted.

Returns: 0 in case of success and -1 in case of failure.

Throws: LibvirtException

See Also: Libvirt Documentation

attachDevice

public void attachDevice(String xmlDesc)
Creates a virtual device attachment to backend.

Parameters: xmlDesc XML description of one device

Throws: LibvirtException

See Also: Libvirt Documentation

attachDeviceFlags

public void attachDeviceFlags(String xmlDesc, int flags)
Creates a virtual device attachment to backend.

Parameters: xmlDesc XML description of one device flags the an OR'ed set of virDomainDeviceModifyFlags

Throws: LibvirtException

See Also: Libvirt Documentation

blockInfo

public DomainBlockInfo blockInfo(String path)
This function returns block device (disk) stats for block devices attached to the domain.

Parameters: path the path to the block device

Returns: the info, or null if an error

Throws: LibvirtException

blockStats

public DomainBlockStats blockStats(String path)
Returns block device (disk) stats for block devices attached to this domain. The path parameter is the name of the block device. Get this by calling virDomainGetXMLDesc and finding the attribute within //domain/devices/disk. (For example, "xvda"). Domains may have more than one block device. To get stats for each you should make multiple calls to this function. Individual fields within the DomainBlockStats object may be returned as -1, which indicates that the hypervisor does not support that particular statistic.

Parameters: path path to the block device

Returns: the statistics in a DomainBlockStats object

Throws: LibvirtException

coreDump

public void coreDump(String to, int flags)
Dumps the core of this domain on a given file for analysis. Note that for remote Xen Daemon the file path will be interpreted in the remote host.

Parameters: to path for the core file flags extra flags, currently unused

Throws: LibvirtException

cpuMapLength

public int cpuMapLength(int maxCpus)
It returns the length (in bytes) required to store the complete CPU map between a single virtual & all physical CPUs of a domain.

create

public int create()
Launches this defined domain. If the call succeed the domain moves from the defined to the running domains pools.

Throws: LibvirtException

create

public int create(int flags)
Launches this defined domain with the provide flags. If the call succeed the domain moves from the defined to the running domains pools.

Throws: LibvirtException

destroy

public void destroy()
Destroys this domain object. The running instance is shutdown if not down already and all resources used by it are given back to the hypervisor. The data structure is freed and should not be used thereafter if the call does not return an error. This function may requires priviledged access

Throws: LibvirtException

detachDevice

public void detachDevice(String xmlDesc)
Destroys a virtual device attachment to backend.

Parameters: xmlDesc XML description of one device

Throws: LibvirtException

See Also: Libvirt Documentation

detachDeviceFlags

public void detachDeviceFlags(String xmlDesc, int flags)
Destroys a virtual device attachment to backend.

Parameters: xmlDesc XML description of one device

Throws: LibvirtException

See Also: Libvirt Documentation

free

public int free()
Frees this domain object. The running instance is kept alive. The data structure is freed and should not be used thereafter.

Returns: number of references left (>= 0) for success, -1 for failure.

Throws: LibvirtException

getAutostart

public boolean getAutostart()
Provides a boolean value indicating whether the network is configured to be automatically started when the host machine boots.

Returns: the result

Throws: LibvirtException

getConnect

public Connect getConnect()
Provides the connection object associated with a domain.

Returns: the Connect object

getID

public int getID()
Gets the hypervisor ID number for the domain

Returns: the hypervisor ID

Throws: LibvirtException

getInfo

public DomainInfo getInfo()
Extract information about a domain. Note that if the connection used to get the domain is limited only a partial set of the information can be extracted.

Returns: a DomainInfo object describing this domain

Throws: LibvirtException

See Also: Libvirt Documentation

getJobInfo

public DomainJobInfo getJobInfo()
Extract information about progress of a background job on a domain. Will return an error if the domain is not active.

Returns: a DomainJobInfo object describing this domain

Throws: LibvirtException

See Also: Libvirt Documentation

getMaxMemory

public long getMaxMemory()
Retrieve the maximum amount of physical memory allocated to a domain.

Returns: the memory in kilobytes

Throws: LibvirtException

getMaxVcpus

public int getMaxVcpus()
Provides the maximum number of virtual CPUs supported for the guest VM. If the guest is inactive, this is basically the same as virConnectGetMaxVcpus. If the guest is running this will reflect the maximum number of virtual CPUs the guest was booted with.

Returns: the number of VCPUs

Throws: LibvirtException

getName

public String getName()
Gets the public name for this domain

Returns: the name

Throws: LibvirtException

getOSType

public String getOSType()
Gets the type of domain operation system.

Returns: the type

Throws: LibvirtException

getSchedulerParameters

public SchedParameter[] getSchedulerParameters()
Gets the scheduler parameters.

Returns: an array of SchedParameter objects

Throws: LibvirtException

getSchedulerType

public String[] getSchedulerType()
Gets the scheduler type.

Returns: the type of the scheduler

Throws: LibvirtException

getUUID

public int[] getUUID()
Get the UUID for this domain.

Returns: the UUID as an unpacked int array

Throws: LibvirtException

See Also: rfc4122

getUUIDString

public String getUUIDString()
Gets the UUID for this domain as string.

Returns: the UUID in canonical String format

Throws: LibvirtException

See Also: rfc4122

getVcpusCpuMaps

public int[] getVcpusCpuMaps()
Returns the cpumaps for this domain Only the lower 8 bits of each int in the array contain information.

Returns: a bitmap of real CPUs for all vcpus of this domain

Throws: LibvirtException

getVcpusInfo

public VcpuInfo[] getVcpusInfo()
Extracts information about virtual CPUs of this domain

Returns: an array of VcpuInfo object describing the VCPUs

Throws: LibvirtException

getXMLDesc

public String getXMLDesc(int flags)
Provides an XML description of the domain. The description may be reused later to relaunch the domain with createLinux().

Parameters: flags not used

Returns: the XML description String

Throws: LibvirtException

See Also: The XML Description format

hasCurrentSnapshot

public int hasCurrentSnapshot()
Determine if the domain has a snapshot

Returns: 1 if running, 0 if inactive, -1 on error

Throws: LibvirtException

See Also: hasManagedSaveImage

public int hasManagedSaveImage()
Determine if the domain has a managed save image

Returns: 0 if no image is present, 1 if an image is present, and -1 in case of error

Throws: LibvirtException

See Also: .String)" id="interfaceStats(.String)">interfaceStats

public DomainInterfaceStats interfaceStats(String path)
Returns network interface stats for interfaces attached to this domain. The path parameter is the name of the network interface. Domains may have more than network interface. To get stats for each you should make multiple calls to this function. Individual fields within the DomainInterfaceStats object may be returned as -1, which indicates that the hypervisor does not support that particular statistic.

Parameters: path path to the interface

Returns: the statistics in a DomainInterfaceStats object

Throws: LibvirtException

isActive

public int isActive()
Determine if the domain is currently running

Returns: 1 if running, 0 if inactive, -1 on error

Throws: LibvirtException

See Also: Libvirt Documentation

isPersistent

public int isPersistent()
Determine if the domain has a persistent configuration which means it will still exist after shutting down

Returns: 1 if persistent, 0 if transient, -1 on error

Throws: LibvirtException

See Also: Libvirt Documentation

managedSave

public int managedSave()
suspend a domain and save its memory contents to a file on disk.

Returns: 0 in case of success or -1 in case of failure

Throws: LibvirtException

See Also: Libvirt Documentation

managedSaveRemote

public int managedSaveRemote()
Remove any managed save images from the domain

Returns:

Throws: LibvirtException

See Also: Libvirt Documentation

memoryStats

public MemoryStatistic[] memoryStats(int number)
This function provides memory statistics for the domain.

Parameters: number the number of stats to retrieve

Returns: the collection of stats, or null if an error occurs.

Throws: LibvirtException

migrate

public Domain migrate(Connect dconn, long flags, String dname, String uri, long bandwidth)
Migrate this domain object from its current host to the destination host given by dconn (a connection to the destination host). Flags may be one of more of the following: Domain.VIR_MIGRATE_LIVE Attempt a live migration. If a hypervisor supports renaming domains during migration, then you may set the dname parameter to the new name (otherwise it keeps the same name). If this is not supported by the hypervisor, dname must be NULL or else you will get an error. Since typically the two hypervisors connect directly to each other in order to perform the migration, you may need to specify a path from the source to the destination. This is the purpose of the uri parameter.If uri is NULL, then libvirt will try to find the best method. Uri may specify the hostname or IP address of the destination host as seen from the source, or uri may be a URI giving transport, hostname, user, port, etc. in the usual form. Uri should only be specified if you want to migrate over a specific interface on the remote host. For Qemu/KVM, the uri should be of the form "tcp://hostname[:port]". This does not require TCP auth to be setup between the connections, since migrate uses a straight TCP connection (unless using the PEER2PEER flag, in which case URI should be a full fledged libvirt URI). Refer also to driver documentation for the particular URIs supported. If set to 0, libvirt will choose a suitable default. Some hypervisors do not support this feature and will return an error if bandwidth is not 0. To see which features are supported by the current hypervisor, see Connect.getCapabilities, /capabilities/host/migration_features. There are many limitations on migration imposed by the underlying technology - for example it may not be possible to migrate between different processors even with the same architecture, or between different types of hypervisor.

Parameters: dconn destination host (a Connect object) flags flags dname (optional) rename domain to this at destination uri (optional) dest hostname/URI as seen from the source host bandwidth optional) specify migration bandwidth limit in Mbps

Returns: the new domain object if the migration was successful, or NULL in case of error. Note that the new domain object exists in the scope of the destination connection (dconn).

Throws: LibvirtException

migrateSetMaxDowntime

public int migrateSetMaxDowntime(long downtime)
Sets maximum tolerable time for which the domain is allowed to be paused at the end of live migration.

Parameters: downtime the time to be down

Returns: 0 in case of success, -1 otherwise.

Throws: LibvirtException

See Also: LIbvirt Documentation

migrateToURI

public int migrateToURI(String uri, long flags, String dname, long bandwidth)
Migrate the domain object from its current host to the destination host given by duri.

Parameters: uri The destination URI flags Controls the migrate dname The name at the destnation bandwidth Specify the migration bandwidth

Returns: 0 if successful, -1 if not

Throws: LibvirtException

See Also: http ://www.libvirt.org/html/libvirt-libvirt.html#virDomainMigrateToURI

pinVcpu

public void pinVcpu(int vcpu, int[] cpumap)
Dynamically changes the real CPUs which can be allocated to a virtual CPU. This function requires priviledged access to the hypervisor.

Parameters: vcpu virtual cpu number cpumap bit map of real CPUs represented by the the lower 8 bits of each int in the array. Each bit set to 1 means that corresponding CPU is usable. Bytes are stored in little-endian order: CPU0-7, 8-15... In each byte, lowest CPU number is least significant bit.

Throws: LibvirtException

processError

protected void processError()
Error handling logic to throw errors. Must be called after every libvirt call.

reboot

public void reboot(int flags)
Reboot this domain, the domain object is still usable there after but the domain OS is being stopped for a restart. Note that the guest OS may ignore the request.

Parameters: flags extra flags for the reboot operation, not used yet

Throws: LibvirtException

resume

public void resume()
Resume this suspended domain, the process is restarted from the state where it was frozen by calling virSuspendDomain(). This function may requires privileged access

Throws: LibvirtException

revertToSnapshot

public int revertToSnapshot(DomainSnapshot snapshot)
Revert the domain to a given snapshot.

Parameters: snapshot the snapshot to revert to

Returns: 0 if the creation is successful, -1 on error.

Throws: LibvirtException

See Also: Libvirt Documentation

save

public void save(String to)
Suspends this domain and saves its memory contents to a file on disk. After the call, if successful, the domain is not listed as running anymore (this may be a problem). Use Connect.virDomainRestore() to restore a domain after saving.

Parameters: to path for the output file

Throws: LibvirtException

setAutostart

public void setAutostart(boolean autostart)
Configures the network to be automatically started when the host machine boots.

Parameters: autostart

Throws: LibvirtException

setMaxMemory

public void setMaxMemory(long memory)
* Dynamically change the maximum amount of physical memory allocated to a domain. This function requires priviledged access to the hypervisor.

Parameters: memory the amount memory in kilobytes

Throws: LibvirtException

setMemory

public void setMemory(long memory)
Dynamically changes the target amount of physical memory allocated to this domain. This function may requires priviledged access to the hypervisor.

Parameters: memory in kilobytes

Throws: LibvirtException

setSchedulerParameters

public void setSchedulerParameters(SchedParameter[] params)
Changes the scheduler parameters

Parameters: params an array of SchedParameter objects to be changed

Throws: LibvirtException

setVcpus

public void setVcpus(int nvcpus)
Dynamically changes the number of virtual CPUs used by this domain. Note that this call may fail if the underlying virtualization hypervisor does not support it or if growing the number is arbitrary limited. This function requires priviledged access to the hypervisor.

Parameters: nvcpus the new number of virtual CPUs for this domain

Throws: LibvirtException

shutdown

public void shutdown()
Shuts down this domain, the domain object is still usable there after but the domain OS is being stopped. Note that the guest OS may ignore the request. TODO: should we add an option for reboot, knowing it may not be doable in the general case ?

Throws: LibvirtException

snapshotCreateXML

public DomainSnapshot snapshotCreateXML(String xmlDesc)
Creates a new snapshot of a domain based on the snapshot xml contained in xmlDesc.

Parameters: xmlDesc string containing an XML description of the domain

Returns: the snapshot, or null on Error

Throws: LibvirtException

See Also: Libvirt Documentation

snapshotCurrent

public DomainSnapshot snapshotCurrent()
Get the current snapshot for a domain, if any.

Returns: the snapshot, or null on Error

Throws: LibvirtException

See Also: Libvirt Documentation

snapshotListNames

public String[] snapshotListNames()
Collect the list of domain snapshots for the given domain.

Returns: The list of names, or null if an error

Throws: LibvirtException

See Also: Libvirt Documentation

snapshotLookupByName

public DomainSnapshot snapshotLookupByName(String name)
Retrieve a snapshot by name

Parameters: name the name

Returns: The located snapshot, or null if an error

Throws: LibvirtException

See Also: Libvirt Documentation

snapshotNum

public int snapshotNum()
Provides the number of domain snapshots for this domain..

See Also: Libvirt Documentation

suspend

public void suspend()
Suspends this active domain, the process is frozen without further access to CPU resources and I/O but the memory used by the domain at the hypervisor level will stay allocated. Use Domain.resume() to reactivate the domain. This function requires priviledged access.

Throws: LibvirtException

undefine

public void undefine()
undefines this domain but does not stop it if it is running

Throws: LibvirtException

updateDeviceFlags

public int updateDeviceFlags(String xml, int flags)
Change a virtual device on a domain

Parameters: xml the xml to update with flags controls the update

Returns: 0 in case of success, -1 in case of failure.

Throws: LibvirtException

See Also: Libvirt Documentation