Comment 6 for bug 1715569

Writing out the xml before and after the update the update function changes the address.

It turns this:

disk device="disk" type="network">
 <driver cache="writeback" name="qemu" type="raw"/>
 <auth username="cinder">
  <secret type="ceph" uuid="1a790a26-dd49-4825-8d16-3dd627cf05a9"/>
 </auth>
 <source name="cinder-volumes/volume-de400476-b68a-45a2-b04f-739313f42bef" protocol="rbd">
  <host name="172.16.128.101" port="6789"/>
  <host name="172.16.128.121" port="6789"/>
  <host name="172.16.128.130" port="6789"/>
 </source>
 <target bus="scsi" dev="sdb"/>
 <serial>de400476-b68a-45a2-b04f-739313f42bef</serial>
 <address bus="0" controller="0" target="0" type="drive" unit="1"/>
</disk>

Into this:

<disk device="disk" type="network">
 <driver cache="writeback" name="qemu" type="raw"/>
 <auth username="cinder">
  <secret type="ceph" uuid="1a790a26-dd49-4825-8d16-3dd627cf05a9"/>
 </auth>
 <source name="cinder-volumes/volume-de400476-b68a-45a2-b04f-739313f42bef" protocol="rbd">
  <host name="172.16.128.101" port="6789"/>
  <host name="172.16.128.121" port="6789"/>
  <host name="172.16.128.130" port="6789"/>
 </source>
 <target bus="scsi" dev="sdb"/>
 <serial>de400476-b68a-45a2-b04f-739313f42bef</serial>
 <address controller="0" type="drive"/>
</disk>