Hello,
I'm trying to move a disk from one storage domain A to another B in oVirt 4.1
The corresponding VM is powered on in the mean time

When executing the action, there was already in place a disk move from storage domain C to A (this move was for a disk of a powered off VM and then completed ok)
I got this in events of webadmin gui for the failed move A -> B:

Feb 20, 2017 2:42:00 PM Failed to complete snapshot 'Auto-generated for Live Storage Migration' creation for VM 'dbatest6'.
Feb 20, 2017 2:40:51 PM VDSM ovmsrv06 command HSMGetAllTasksStatusesVDS failed: Error creating a new volume
Feb 20, 2017 2:40:51 PM Snapshot 'Auto-generated for Live Storage Migration' creation for VM 'dbatest6' was initiated by admin@internal-authz.


And in relevant vdsm.log of referred host ovmsrv06

2017-02-20 14:41:44,899 ERROR (tasks/8) [storage.Volume] Unexpected error (volume:1087)
Traceback (most recent call last):
  File "/usr/share/vdsm/storage/volume.py", line 1081, in create
    cls.newVolumeLease(metaId, sdUUID, volUUID)
  File "/usr/share/vdsm/storage/volume.py", line 1361, in newVolumeLease
    return cls.manifestClass.newVolumeLease(metaId, sdUUID, volUUID)
  File "/usr/share/vdsm/storage/blockVolume.py", line 310, in newVolumeLease
    sanlock.init_resource(sdUUID, volUUID, [(leasePath, leaseOffset)])
SanlockException: (-202, 'Sanlock resource init failure', 'Sanlock exception')
2017-02-20 14:41:44,900 ERROR (tasks/8) [storage.TaskManager.Task] (Task='d694b892-b078-4d86-a035-427ee4fb3b13') Unexpected error (task:870)
Traceback (most recent call last):
  File "/usr/share/vdsm/storage/task.py", line 877, 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 1929, in createVolume
    initialSize=initialSize)
  File "/usr/share/vdsm/storage/sd.py", line 762, in createVolume
    initialSize=initialSize)
  File "/usr/share/vdsm/storage/volume.py", line 1089, in create
    (volUUID, e))
VolumeCreationError: Error creating a new volume: (u"Volume creation d0d938bd-1479-49cb-93fb-85b6a32d6cb4 failed: (-202, 'Sanlock resource init failure', 'Sanlock exception')",)
2017-02-20 14:41:44,941 INFO  (tasks/8) [storage.Volume] Metadata rollback for sdUUID=900b1853-e192-4661-a0f9-7c7c396f6f49 offs=8 (blockVolume:448)


Was the error generated due to the other migration still in progress?
Is there a limit of concurrent migrations from/to a particular storage domain?

Now I would like to retry, but I see that the disk is in state locked with hourglass.
The autogenerated snapshot of the failed action was apparently removed with success as I don't see it.

How can I proceed to move the disk?

Thanks in advance,
Gianluca