This line can be filled in with a good description: https://github.com/openstack/nova/blob/ef2203f36fc0bde2635e0d1f39a4b8dce5654ffb/nova/conf/libvirt.py#L635
and here are the choices: 'raw', 'flat', 'qcow2', 'lvm', 'rbd', 'ploop', 'default'.
This line can be filled in with a good description: https:/ /github. com/openstack/ nova/blob/ ef2203f36fc0bde 2635e0d1f39a4b8 dce5654ffb/ nova/conf/ libvirt. py#L635
and here are the choices: 'raw', 'flat', 'qcow2', 'lvm', 'rbd', 'ploop', 'default'.