<disk device='disk'>
  <driver name='qemu' type='ploop'/>
  <source file='/path/to/i.img'>
    <privateData>
      <nodenames>
        <nodename type='storage' name='test2'/>
        <nodename type='format' name='test1'/>
      </nodenames>
    </privateData>
  </source>
  <target dev='vda'/>
</disk>