The backup did run over SAN and after a VEAgent problem some VM backup’s are now passing over NBD instead.
Typical message in the session report:
Virtual Machine 'VM': Backup disk scsiX:X using transport method NBD
The most probable reason is the SAN lock from VMware was not released.
Manual cleaning up the data is the only solution.
Note: If only a NBD transport mode exits, the backup will fail since no other transport mode is then available.
Virtual Machine 'VM': Could not backup disk scsi0:0 ...
When no backups are running have a look on the VEAgent backup host.
The place where VMware sets its lock files is C:\Windows\Temp\vmware-SYSTEM
This folder should be free of any uuid#-vm-XXXX folders, for example:
10/01/2012 07:56 PM <DIR> 420e8db6-5146-8aaf-5596-1dc7c738c1a1-vm-27
Directory of C:\Windows\Temp\vmware-SYSTEM\420e8db6-5146-8aaf-5596-1dc7c738c1a1-vm-27
10/01/2012 07:56 PM <DIR> .
10/01/2012 07:56 PM <DIR> ..
10/01/2012 07:56 PM <DIR> LOCK.lck
10/01/2012 07:56 PM <DIR> nbd
10/01/2012 07:56 PM <DIR> san
When the folder is deleted, the file LOCK.lck is removed
To release this VM, the folder 420e8db6-5146-8aaf-5596-1dc7c738c1a1-vm-27 should be removed.
Verify that no backups VEagent backups are active!
Note that this directory has special permissions and can only be removed if permissions are changed first.
Select folder, properties, security tab.
Select "Edit" and allow administrators "full control", apply and answer "yes" to continue and now delete the directory.
When L6 Trivia debugs are enabled the following message will be logged:
2012-11-09T14:16:23.215 01:00 [02212 error 'Default']
Cannot use advanced transport modes for vcenter.hp.com:443/moref=vm-27/snapshot-27: Cannot create directory C:\Windows\TEMP\vmware-SYSTEM\420e8db6-5146-8aaf-5596-1dc7c738c1a1-vm-27.