The problem itself seems related with snapshot and with the disk (430Gb in size).

Failed to complete snapshot 'test3' creation for VM 'dbatest6'.

VDSM ovmsrv07 command HSMGetAllTasksStatusesVDS failed: Could not acquire resource. Probably resource factory threw an exception.: ()

Snapshot 'test3' creation for VM 'dbatest6' was initiated by admin@internal-authz.

The VM is composed by 2 disks, that are on 2 different storage domains.

I'm able to create and then delete a snapshot that includes only the first system disk (no memory saved), but I receive the same error as in the move disk if I try to do a snapshot including instead only the second disk (again no memory save).

In this case the disk doesn't remain locked as it happened when trying to move the disk...

Can it help in any way to shutdown the VM?

I should free this storage domain and this is the only disk remained before decommission...

Thanks,

Gianluca