<domainsnapshot> <name>my snap name</name> <description>!@#$%^</description> <disks> <disk name='hdd' snapshot='external'> <source file='/path/to/new'/> <driver type='qcow2'> <metadata_cache> <max_size unit='bytes'>1234</max_size> </metadata_cache> </driver> </disk> </disks> </domainsnapshot>