Windows Server Backup Retention Policy-Can It be Specified?

Posted by @Cody

April 14, 2016

Understand the Windows Server Backup retention policy and learn to make the best practice of backup retention policy.

About the retention policy

Many people use Windows Server Backup to backup their servers and files. However, after running backups for a while, they do have some doubts. Why did Windows Server Backup not doing incremental backup though incremental backup is configured? Why did it only keep one backup in the backup drive? How did backup disk become full? To break these down, you must understand the Windows Server Backup retention policy. Windows Server Backup has automatic disk usage management function that will delete old backup versions when there is no enough space for the current backup. The retention policy is a certain rule to determine which backups to delete.

How does the retention policy works?

As you know, Windows Server Backup save the backup versions in volume shadow copies by creating a shadow copy of the backup volume after a new backup is complete. Since the old backup versions are saved in shadow copies, you cannot delete it in File Explorer and you can only see the latest backup saved as a VHD file or VHDX file(since Windows Server 2012). To save the shadow copies, Windows Server Backup will locate a certain space called diff area. If the program detects that the backup drive has insufficient space for the new backup to come, it will automatically delete the oldest backup version to free some space by shrinking the diff area. Nevertheless, it will stop shrinking the allocated space for shadow copies when the diff area is about 1/8 of the backup volume size. Therefore, your backup will fail because of backup disk full. When the backup disk gets filled, you can use WBadmin delete backup to delete old backups to free up space.

Since there is no way to create volume shadow copy of a network shared folder, scheduled backups on network location will only be performed as full backup. What’s worse, the new backup will overwrite the previous one, which is to say that you may have none backup if the backup fails in the middle. Therefore, the Windows Server Backup retention period is not referring to network backup. If you need a better backup retention policy or prefer network backup solution, you can use third party backup software for Windows Server instead of Windows Server Backup.

Specify backup retention policy as you like

Windows Server Backup program, AOMEI Backupper Server allows you to backup system, files, partitions, and disks to any locations shown in File Explorer, and it gives you 5 ways of old backups cleanup, which you can specify depending on your needs. Besides, you can set up an email notification to notify your whether the backup is complete or failed. To make backup retention policy best practice, you can use AOMEI Backupper Server.

1. Download, and run this server backup tool.

2. Under the “Backup” tab, you can see four types of backup, System Backup, Disk Backup, Partition Backup, and File Backup.Select “System Backup” here as an example.

System Backup

3. Since the program will include the system related items into the backup automatically, click “Step 2” to decide where you want to put the image backups

Destination Location

4. Click on the “Schedule” button down the window to create a scheduled backup, and then “Scheme” to select a backup scheme referring to the backup retention policy template.

Backup Scheme

5. At last, click “Start Backup” to make this backup task on schedule.

Start Backup

If your server happens to be in serious situation, you can easily restore your server to eariler state, and restore to dissimilar hardware is also supported. As a conclusion, if you are not confortable with Windows Server Backup retention policy, AOMEI Backupper is your best backup program for your Windows Server 2008/2012/2012.