On 10/30/2013 10:44 AM, Eric Blake wrote:
Here's the XML I think we need to add to domainsnapshot:
<domainsnapshot> ... <disks> <disk name='vda' snapshot='external' type='network'> <driver type='qcow2'/> <source protocol='gluster' name='vol1/img2'> <host name='red'/> </source> </disk>
that is, add an optional /disk@type attribute (if absent, it defaults to type='file'), and where if present, the <source> subelement then takes on alternate forms in the same manner in which //domain/devices/disk handles alternates (here, allowing a protocol, name, and host specification).
[Ultimately, we need to fix //domain/devices/disk to specify a full backing chain, but one step at a time...]
This does match the XML that my (prototype) Nova code generated in hopes that this would work, except that I didn't have a <driver> element. (Makes sense, I can add this.) <domainsnapshot> <disks> <disk name="vdb" snapshot="external" type="network"> <source protocol="gluster" name="gvol1/volume-931536e0-65a7-4bd9-85ed-48bdd0160642.f6e62e4c-17b9-49bd-8941-10e8d11a22ca"> <host name="127.0.0.1"/> </source> </disk> <disk name="/opt/stack/data/nova/instances/6ff2075e-7b23-492a-865a-e7f8269d95bb/disk" snapshot="no"/> </disks> </domainsnapshot> $ qemu-img info volume-931536e0-65a7-4bd9-85ed-48bdd0160642.f6e62e4c-17b9-49bd-8941-10e8d11a22ca image: volume-931536e0-65a7-4bd9-85ed-48bdd0160642.f6e62e4c-17b9-49bd-8941-10e8d11a22ca file format: qcow2 virtual size: 1.0G (1073741824 bytes) disk size: 193K cluster_size: 65536 backing file: volume-931536e0-65a7-4bd9-85ed-48bdd0160642 backing file format: raw