<disk device='disk' name='vda' type='network'>
  <driver type='qcow2'/>
  <source protocol='sheepdog' name='asdf/i.qcow2'>
    <host name='example.com' port='1234'/>
    <privateData>
      <nodenames>
        <nodename type='storage' name='0123456789ABCDEF0123456789ABCDE'/>
        <nodename type='format' name='0123456789ABCDEF0123456789ABCDE'/>
      </nodenames>
    </privateData>
  </source>
</disk>