Hi, I performed the following: - 1. Shutdown VM. 2. Take a snapshot 3. Create a clone from snapshot. 4. Start the clone. Clone starts fine. 5. Attempt to delete snapshot from original VM, fails. 6. Attempt to start original VM, fails with "Bad volume specification". This was logged in VDSM during the snapshot deletion attempt. 2019-02-26 13:27:10,907+0000 ERROR (tasks/3) [storage.TaskManager.Task] (Task='67577e64-f29d-4c47-a38f-e54b905cae03') Unexpected error (task:872) Traceback (most recent call last): File "/usr/share/vdsm/storage/task.py", line 879, in _run return fn(*args, **kargs) File "/usr/share/vdsm/storage/task.py", line 333, in run return self.cmd(*self.argslist, **self.argsdict) File "/usr/lib/python2.7/site-packages/vdsm/storage/securable.py", line 79, in wrapper return method(self, *args, **kwargs) File "/usr/share/vdsm/storage/sp.py", line 1892, in finalizeMerge merge.finalize(subchainInfo) File "/usr/share/vdsm/storage/merge.py", line 271, in finalize optimal_size = subchain.base_vol.optimal_size() File "/usr/share/vdsm/storage/blockVolume.py", line 440, in optimal_size check = qemuimg.check(self.getVolumePath(), qemuimg.FORMAT.QCOW2) File "/usr/lib/python2.7/site-packages/vdsm/qemuimg.py", line 157, in check out = _run_cmd(cmd) File "/usr/lib/python2.7/site-packages/vdsm/qemuimg.py", line 426, in _run_cmd raise QImgError(cmd, rc, out, err) QImgError: cmd=['/usr/bin/qemu-img', 'check', '--output', 'json', '-f', 'qcow2', '/rhev/data-center/mnt/blockSD/024109d5-ea84-47ed-87e5-1c8681fdd177/images/f7dea7bd-04 6c-4923-b5a5-d0c1201607fc/ac540314-989d-42c2-9e7e-3907eedbe27f'], ecode=3, stdout={ "image-end-offset": 52210892800, "total-clusters": 1638400, "check-errors": 0, "leaks": 323, "leaks-fixed": 0, "allocated-clusters": 795890, "filename": "/rhev/data-center/mnt/blockSD/024109d5-ea84-47ed-87e5-1c8681fdd177/images/f7dea7bd-046c-4923-b5a5-d0c1201607fc/ac540314-989d-42c2-9e7e-3907eedbe27f", "format": "qcow2", "fragmented-clusters": 692941 } , stderr=Leaked cluster 81919 refcount=1 reference=0 Leaked cluster 81920 refcount=1 reference=0 Leaked cluster 81921 refcount=1 reference=0 etc.. Is there any way to fix these leaked clusters? Running oVirt 4.1.9 with FC block storage. Thanks, Alan