5.3. Pool usage

⁠5.3. Pool usage

There are a number of methods available in the virStoragePool class. The following example program features a number of the methods which describe some attributes of a pool.

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Example 5.2. Show the usage of some storage pool methods

# Example-2.py
#!/usr/bin/env python3
import sys
import libvirt

conn = None
try:
    conn = libvirt.open("qemu:///system")
except libvirt.libvirtError as e:
    print(repr(e), file=sys.stderr)
    exit(1)

pool = conn.storagePoolLookupByName('default')
if pool == None:
    print('Failed to locate any StoragePool objects.', file=sys.stderr)
    exit(1)

info = pool.info()

print('Pool: '+pool.name())
print('  UUID: '+pool.UUIDString())
print('  Autostart: '+str(pool.autostart()))
print('  Is active: '+str(pool.isActive()))
print('  Is persistent: '+str(pool.isPersistent()))
print('  Num volumes: '+str(pool.numOfVolumes()))
print('  Pool state: '+str(info[0]))
print('  Capacity: '+str(info[1]))
print('  Allocation: '+str(info[2]))
print('  Available: '+str(info[3]))

conn.close()
exit(0)

Many of the methods shown in the previous example provide information concerning storage pools that are on remote file systems, disk systems, or types other that local file systems. For instance. if the autostart flag is set then when the user connects to the storage pool libvirt will automatically make the storage pool available if it is not on a local file system e.g. an NFS mount. Storage pools on local file systems also need to be started if the autostart is not set.

The isActive method indicates whether or not the user must activate the storage pool in some way. The create method can activate a storage pool.

The isPersistent method indicates whether or not a storage pool needs to be activated using create method. A value of 1 indicates that the storage pool is persistent and will remain on the file system after it is released.

The flags parameter can be one or more of the following constants:

VIR_STORAGE_XML_INACTIVE

The following example shows how to get the XML description of a storage pool.

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Example 5.3. Get the XML description of a storage pool

# Example-3.py
#!/usr/bin/env python3
import sys
import libvirt

conn = None
try:
    conn = libvirt.open("qemu:///system")
except libvirt.libvirtError as e:
    print(repr(e), file=sys.stderr)
    exit(1)

pool = conn.storagePoolLookupByName('default')
if pool == None:
    print('Failed to locate any StoragePool objects.', file=sys.stderr)
    exit(1)
xml = pool.XMLDesc(0)
print(xml)

conn.close()
exit(0)