<domainbackup mode='push'>
  <incremental>1525889631</incremental>
  <disks>
    <disk name='vda' backup='yes' type='file' backupmode='incremental' incremental='1525889631'>
      <driver type='raw'/>
      <target file='/path/to/file'/>
    </disk>
    <disk name='hda' backup='no'/>
    <disk name='vdextradisk' backup='no'/>
  </disks>
</domainbackup>