I performed the following: -

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.

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..

Running oVirt 4.1.9 with FC block storage.