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