Windows Server Backup: Swapping Target Drives

I’m running Window Server Backup on Windows Server 2008 R2. Like a good admin, I swap out destination drives, rotating one drive off site each week.

Can’t Add Second Drive

Using the Windows Server Backup GUI, I set up a backup schedule to do backups to the G: drive and ran backups for a few days. Then I swapped in a new drive. The backup failed with Event ID 561 followed by the more helpful Event ID 546:

Log Name:      Application
Source:        Microsoft-Windows-Backup
Event ID:      546
Task Category: None
Level:         Error
Description: The backup operation attempted at ‘‎2010‎-‎09‎-‎13T04:00:16.334849700Z’ has failed to start, error code ‘2155348061’ (Windows Backup cannot find any of the backup storage locations.). Please review the event details for a solution, and then rerun the backup operation once the issue is resolved.

Okay, so re-run the backup schedule wizard and choose Modify backup storage destinations. Interesting, the old drive G: is now listed as a Volume ID. I guess that makes sense since it is not mounted. Add the current drive G:

Click Next and then Finish the wizard. What? “The filename, directory name, or volume label syntax is incorrect.”

Knowledge Base Incomplete

This must be a common problems, because Microsoft Knowledge Base article 2009365 addresses it specifically:

Error message when you try to add an additional disk to a scheduled backup: “The filename, directory name, or volume label syntax is incorrect”

In my case, the drives are mounted in a Vantec EZ-Swap bay, so I can only mount one at a time. I’m therefore left with Option 3 of the KB article, namely running wbadmin to add the extra target drive. However when I follow their instructions to add the target using the Disk Identifier, I get a long message telling me that it will wipe out my old storage locations:

Apparently when you specify a Disk Identifier, it’s telling Windows Server Backup to consume and format the entire target disk. Since I use the disk for other backups, I need Windows Server Backup to treat it is as a Volume, not a Disk.

Specify Additional Volume Target

The solution is simple:  specify the drive letter instead of the Disk Identifier when adding the target. For example:

wbadmin enable backup -addTarget:G:

Once that Volume target was added, I was able to successfully run a backups to the second backup disk.