Adam Litke has posted comments on this change.
Change subject: Live Merge: Get volume chain for multiple drives ......................................................................
Patch Set 2:
(1 comment)
http://gerrit.ovirt.org/#/c/31366/2/vdsm/virt/vm.py File vdsm/virt/vm.py:
Line 5398: Line 5399: # Check that libvirt exposes full volume chain information Line 5400: try: Line 5401: ret = self._driveGetActualVolumeChain([drive])[drive['alias']] Line 5402: except KeyError:
I'm missing why this is now needed
It is not yet possible to tell if libvirt will expose backing chain information in the domain's live xml by API introspection. We must check if this VM has it to be certain.
You're right that we don't need to keep the chain in the tracked blockJob anymore. This was needed by an older method of high write watermark detection. I'll remove it. Line 5403: self.log.error("merge: libvirt does not support volume chain " Line 5404: "monitoring. Unable to perform live merge.") Line 5405: return errCode['mergeErr'] Line 5406: chain = _volumeChainToVolumeIds(ret)