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