[ovirt-users] Cannot remove snapshot

Hello, oVirt 3.6.7.5-1 I'm trying to remove a snapshot in a cold way (VM shut down). It is failing, and VDSM is telling : 4f1588f3-ae2d-4702-b7e1-4ef53b5b5a1d::DEBUG::2017-11-17 13:04:11,448::lvm::290::Storage.Misc.excCmd::(cmd) SUCCESS: <err> = ' WARNING: lvmetad is running but disabled. Restart lvmetad before enabling it!\n'; <rc> = 0 4f1588f3-ae2d-4702-b7e1-4ef53b5b5a1d::DEBUG::2017-11-17 13:04:11,456::lvm::462::Storage.LVM::(_reloadlvs) lvs reloaded 4f1588f3-ae2d-4702-b7e1-4ef53b5b5a1d::DEBUG::2017-11-17 13:04:11,456::lvm::462::Storage.OperationMutex::(_reloadlvs) Operation 'lvm reload operation' released the operation mutex 4f1588f3-ae2d-4702-b7e1-4ef53b5b5a1d::ERROR::2017-11-17 13:04:11,457::image::1302::Storage.Image::(merge) Unexpected error Traceback (most recent call last): File "/usr/share/vdsm/storage/image.py", line 1293, in merge sdDom, srcVolParams, volParams, reqSize, chain) File "/usr/share/vdsm/storage/image.py", line 1039, in _baseCowVolumeMerge unsafe=False, rollback=True) File "/usr/share/vdsm/storage/volume.py", line 278, in rebase raise se.MergeSnapshotsError(self.volUUID) MergeSnapshotsError: Error merging snapshots: ('4a8c17aa-5882-45a1-8a6e-40db39ed06ca',) I read this : https://bugzilla.redhat.com/show_bug.cgi?id=1069610 , hoping I could find some workaround. But I couldn't. If there is no abvious workaround, would there be other ways like : - find the bare logical volume, shut down the VM, and play with low level qemu-img commands. I think I knwn how to do that, but I'm worried the oVirt database won't be in sync once I've removed the snapshot or - export the VM then re-import, if this is related to some LV space missing. Then removing the snapshot the usual way. Any advice (apart the obvious upgrade-to-4.X-sir)? -- Nicolas ECARNOT