The Solution to Windows Server Backup Disk Full

Posted by @Cody

July 28, 2017

What to do when Windows Server Backup disk full in Windows Server 2008 R2 and 2012 R2? This article will show you how to free up space and the way to solve this problem once for all.

How does Automatic disk usage management work?

Windows Server Backup (WBS) uses automatic disk usage management that can automatically delete old backups to free up disk space. Theoretically, there is no way to cause Windows Server Backup disk full. However, theory is not practice. After running scheduled backups for a while, it is likely that you may find that backup fails for the backup disk is not sufficient. To free space, WSB will shrink the space allocated for snapshots and delete the corresponding backups. WSB allows you to keep shrinking the space for snapshots till it is around 1/8 of the target disk size. Then you will find that your backup disk is full.

Solution to backup disk full

Since Windows Server Backup Automatic Disk Usage Management fails to function, to make your scheduled backup run again when the backup disk is full, you can add a larger disk as the backup disk or manually free some disk space for creating new backups. Windows Server 2012 or later versions of Windows Server, can use wbadmin delete backups command to delete one or more backups. The syntax is WBADMIN DELETE BACKUP -keepVersion:<No. of copies> -BackupTarget:<VolumeName>. However, Windows Server 2008/2008 R2 only allows you to delete system state backup with WBadmin. If it is not system state backups that occupy the room of backup disk, then you can delete some snapshots from command line. To delete snapshots, you can use diskshadow.exe. You can type Diskshadow.exe in the Run box or Start box, and press Enter to open Diskshadow.exe. Then run the following command:

delete shadows oldest <BackupTargetLocation>

Delete Shadow

You can use drive letter or volume GUID to specify the backup target location. By default, the backup disk has no drive letter, but you can manually assign a drive letter with Disk Management. To see the volume GUID, you can run the command:



The next time backup disk is full, you can repeat these operations to clean up windows server backup. If you want to fix this problem once for all, it is recommended to try a different backup program.

Long-term solution

A dedicated Windows Server backup program, AOMEI Backupper Server provides 4 types of backup solution, System Backup, Disk Backup, Partition Backup, and File Backup. Its Disk Space Management can help you to automatically delete the previous image backups in five different schemes. Therefore, you will never see Windows Server Backup filling up drive. What’s more, you can use Task Scheduler or its own service to run scheduled backup task followed by full/incremental/differential backups. Let’s see how it works:

1. Download, install and open this Windows Server backup software.

2. Under “Backup” tab, choose one type of backup that you need. The most often used backup solution System Backup will be taken as an example here.

System Backup

3. System Backup will automatically include the partitions containing system and boot files into the backup. Click Step 2 to choose a target location to save the image backups.

Destination Location

4. Click “Schedule” to configure a schedule for the backup task. Then click the Scheme option to enable Disk Space Management. Select one of the 5 types that suites your needs. Each scheme has dynamic graphics to show you how it works.

Backup Scheme

5. Click Start Backup to finish creating this backup schedule.

Start Backup

The image backups created with AOMEI Backupper can be easily restored to the original location or other location, and even restore to dissimilar hardware computer. With the help of Disk Space Management, you will never find Windows Server backup disk full.