Monday, February 28, 2011

Running chkdsk on a Drive Allocated to Windows Server Backup

Occasionally I see Windows Server Backup throw odd errors pointing to problems with the disk allocated to Windows Server Backup, such as the bizarre “There is not enough space on the disk” – bizarre in that Windows Server Backup is supposed to automagically manage the disk space allocation and tidy up.

The normal course of action would be to run chkdsk /f on the drive, but the drive doesn’t have a drive letter allocated to it. Nor are you supposed to allocate a drive letter to it. The solution? Use the Volume GUID.

To find the Volume GUID, type in the following at an elevated Command Prompt:


This will return the command syntax for the mountvol command, followed by the existing volumes and their mount points. We’re interested in the Volume GUID immediately above this line:


It will look something like this:


We now take this Volume GUID minus the trailing slash and feed it to chkdsk, like this:

chkdsk /f \\?\Volume{12345678-1234-5678-9abc-123456789abc}

This will then allow chkdsk to perform a consistency check and fix of the drive allocated to Windows Server Backup without needing to allocate a drive letter.


Woody said...

When I do this Windows Server 2008 says: "The type of the file system is RAW.
CHKDSK is not available for RAW drives."

How do I fix this drive ?

stryqx said...

@Woody sounds like the drive hasn't been formatted. If it doesn't have any data on it, then you can open Administrative Tools > Computer Management > Storage > Disk Management, create a partition on the drive and format it as NTFS.

stryqx said...

Another reason for a partition showing up as RAW is if the partition has been encrypted by BitLocker.

Anonymous said...

I am having this same issue with the Windows Server Backup. The backups started to fail with error "The system cannot find the file specified". When I try to run chkdsk on this volume it states "The volume is raw" but I never encrypted it. It's definitely NTFS... Did the partition corrupt or something? I feel like I have a problem with Windows Server Backup every day.

Anonymous said...

Many thanks. The root post was very helpful.

Anonymous said...

Just want to point out that you must be running the command prompt as an administrator to run chkdsk on your external drive

Anonymous said...

So, in Windows Server 2012 Essentials, there's a facility to take care of this from the Dashboard. Go to Storage | Drives, then select the Backup drive. From the properties, you can select the "Check and Repair a hard drive" utility. It works, but it's irritating that MS stuck it in the dashboard - chkdsk from disk manager doesn't work.

Anonymous said...

Brilliant. Thank you!

Beau said...

Just want to say thanks for this guide. I've referenced it may times.

sarath v abhilash said...