[ovirt-users] Unable to start VM

Hi all, I did a routine maintenance today (updating the hosts) to ovirt cluster (4.2) and I have one VM that was complaining about an invalid snapshot. After shutdown of VM the VM is not able to start again, giving the error: VM Gitlab is down with error. Exit message: Bad volume specification {'serial': 'b6af2856-a164-484a-afe5-9836bbdd14e8', 'index': 0, 'iface': 'virtio', 'apparentsize': '51838976', 'specParams': {}, 'cache': 'none', 'imageID': 'b6af2856-a164-484a-afe5-9836bbdd14e8', 'truesize': '52011008', 'type': 'disk', 'domainID': '142bbde6-ef9d-4a52-b9da-2de533c1f1bd', 'reqsize': '0', 'format': 'cow', 'poolID': '00000001-0001-0001-0001-000000000311', 'device': 'disk', 'path': '/rhev/data-center/00000001-0001-0001-0001-000000000311/142bbde6-ef9d-4a52-b9da-2de533c1f1bd/images/b6af2856-a164-484a-afe5-9836bbdd14e8/f3125f62-c909-472f-919c-844e0b8c156d', 'propagateErrors': 'off', 'name': 'vda', 'bootOrder': '1', 'volumeID': 'f3125f62-c909-472f-919c-844e0b8c156d', 'diskType': 'file', 'alias': 'ua-b6af2856-a164-484a-afe5-9836bbdd14e8', 'discard': False}. I see also the following error: VDSM command CopyImageVDS failed: Image is not a legal chain: (u'b6af2856-a164-484a-afe5-9836bbdd14e8',) Seems as a corrupt VM disk? The VM had 3 snapshots. I was able to delete one from GUI then am not able to delete the other two as the task fails. Generally I am not allowed to clone, export or do sth to the VM. Have you encountered sth similar. Any advice? Thanx, Alex