libvirt移行kvm仮想マシンmigrate api

libvirtを使用してKVM仮想マシンのホット移行を制御します.ここではmigrateメソッドの使用を記録します. 

import libvirt 
import pprint
conn_004 = libvirt.open(‘qemu+tcp://username@server004/system’) 
conn_005 = libvirt.open(‘qemu+tcp://username@server005/system’) 
vm_domain = conn_004.lookupByName(‘instance_name’) 
vm_domain.migrate(conn_005,True,’instance_name’,None,0)
pprint.pprint(help(vm_domain.migrate))

は、プログラムの出力、すなわちmigrateインタフェースの説明である.
migrate(self, dconn, flags, dname, uri, bandwidth) method of libvirt.virDomain instance Migrate the 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:  VIR_MIGRATE_LIVE : Do not pause the VM during migration  VIR_MIGRATE_PEER2PEER: Direct connection between source & destination hosts  VIR_MIGRATE_TUNNELLED :Tunnel migration data over the libvirt RPC channel  VIR_MIGRATE_PERSIST_DEST :If the migration is successful, persist the domain on the destination host.  VIR_MIGRATE_UNDEFINE_SOURCE :If the migration is successful, undefine the domain on the source host.  VIR_MIGRATE_PAUSED :Leave the domain suspended on the remote side.  VIR_MIGRATE_CHANGE_PROTECTION :Protect against domain configuration changes during the migration process (set automatically when supported).  VIR_MIGRATE_UNSAFE :Force migration even if it is considered unsafe.

VIR_MIGRATE_TUNNELLED requires that VIR_MIGRATE_PEER2PEER be set.
Applications using the VIR_MIGRATE_PEER2PEER flag will probably
prefer to invoke virDomainMigrateToURI, avoiding the need to
open connection to the destination host themselves.

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 None or else you will get an error.

If the VIR_MIGRATE_PEER2PEER flag is set, the uri parameter
must be a valid libvirt connection URI, by which the source
libvirt driver can connect to the destination libvirt. If
omitted, the dconn connection object will be queried for its
current URI.

If the VIR_MIGRATE_PEER2PEER flag is NOT set, the URI parameter
takes a hypervisor specific format. The hypervisor capabilities
XML includes details of the support URI schemes. If omitted
the dconn will be asked for a default URI.

In either case it is typically only necessary to specify a
URI if the destination host has multiple interfaces and a
specific interface is required to transmit migration data.

The maximum bandwidth (in MiB/s) that will be used to do migration
can be specified with the bandwidth parameter.  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 virConnectGetCapabilities, /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.