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Does your backup files take up large space?
There is no denying that backups play a great a role in protecting data considering the event of data loss. While running scheduled backups repeatedly, you will have many backup versions and all these backup versions take a lot of disk space on your hard drive.
At this time, you may choose to delete backup files or use a larger drive as backup destination, but neither of the two solutions can solve this problem. You may mistakenly delete files in need if you use the first solution. And the backup disk may be full sooner or later if replace the smaller drive with a larger one, it's just a matter of time.
Well then, how to solve the problem backup disk full? You need to use backup retention policy in backup software, which has its own rule and can automatically delete old backups to save much disk space while retaining some of the latest backups.
What are the backup retention policy and precaution?
A backup retention policy is a rule that defines how to retain backup files and how long they should be retained. Here I will use backup software AOMEI Backupper Professional to explain in detail for you.
This software has 4 different backup policies, namely, By quantity, By time, By daily/weekly/monthly, and By space. And it allows you to specify the number of backups you want to retain or the backup cycle based on the selected backup scheme. In addition, there is something you need to know before you set backup retention policy for your backup task.
Backup types: You can create system backup, disk backup, partition backup, file backup and cloud backup as per your needs.
Backup Schedule: You can set schedule backup in daily/weekly/monthly backup & full/incremental/differential backup. But you need to know that the deletion of any previous backup versions in the scheduled incremental backup will cause the backup invalid while a differential backup will not, because their basis is different.
Backup Scheme: You can select any of the backup scheme offered by AOMEI Backupper. If you select the incremental backup method, there will be three retention policies available. If you select the differential backup method, there will be four options.
What are backup retention policy best practices?
As mentioned earlier, the backup disk will be full filled if you backup data or system continuously. Therefore, in order to delete old versions of backup files, some users create a batch file to delete old backups created in a certain period of time and use Task Scheduler to run the batch file.
It sounds pretty good, but there are potential problems that may invalidate the backup. If you use scheduled incremental backup, it will keep creating incremental backups after the first full backup by default. Once you accidentally delete one of the previous incremental backup, the backup afterwards will be invalid.
Therefore, if you are not familiar with the way how incremental backup and differential backup work, it is not recommended to manually delete any versions of backup. The best practice is to employ a professional backup software for backup disk space management, you could consider using AOMEI Backupper Professional or its advanced version.
How to easily perform backup retention policy step by step
To automatically delete old backups while keeping the latest backup valid, you could follow the stepwise tutorial below. In the first place, download AOMEI Backupper Professional and install it on your computer. If your compuer use server system, Windows Server 2012, for example, you could consider using AOMEI Backupper Server. Then, prepare a backup disk to store image file.
Step 1. Connect the backup disk to your computer and be sure it's recognized. Launch the professional backup software - AOMEI Backupper, click "Backup" and "File Backup". Also, you can use other backup solutions.
Step 2. Click "Add File" or "Add Folder" to choose files or folders you want to backup.
Step 3. Click where the arrow point to select backup destination. You can backup files to external hard drive, network drive, NAS, or other locations as long as it can be detected by Windows.
Step 4. Click "Schedule Backup" and select daily/weekly/monthly backup, etc. The default option is daily incremental backup.
Step 5. Click "Backup Scheme" and choose the backup method (full/incremental/differential backup). Switch on "Enable Automatic Backup Cleanup" and choose one retention policy. After that, click "Start Backup" to excute the task.
Further reading: four different backup retention policies
“Backup Scheme” is at the lower left corner of a backup solution, such as file backup. Click it and the slide button, and then you will see all the backup schemes. You can select one of them and each backup scheme will make a full backup before performing the scheme (it's the default option). Then, see below and learn them in detail. The cleanup rule will be different based on the backup method you choose.
1). By quantity
- Full Backup: Only keep the last "n" backups. When the number of backups exceeds the set value, the old backups will be automatically deleted.
- Incremental Backup: Only the most recent "n" groups of backups are kept. A backup group includes a full backup and multiple incremental backups. When the number of groups exceeds the set value, the old backup group will be automatically deleted.
- Differential Backup: Only keep the last "n" backups. When the number of backups exceeds the set value, the old backups will be automatically deleted. The differential backup is deleted first, and the full backup is deleted at last.
2). By time
- Full Backup: Only keep backups of the last "n" days/weeks/months. When the backup time exceeds the set value, the old backup will be deleted automatically.
- Incremental Backup: Only keep backups of the last "n" days/weeks/months. When the backup time exceeds the set value, the old backup group will be deleted automatically. A backup group includes a full backup and multiple incremental backups. When the last backup in the group exceeds the set value, the old backup group will be automatically deleted.
- Differential Backup: Only keep backups of the last "n" days/weeks/months. When the backup time exceeds the set value, the old backup will be deleted automatically. The differential backup is deleted first, and the full backup is deleted at last.
3). By daily/weekly/monthly
- Full Backup: In the last "n" days, keep all backups; When the set number of days is exceeded, the old backups will be automatically deleted according to the weekly rule;
In the last "n" weeks, a full backup will be kept every week, and when the set number of weeks is exceeded, the old backups will be automatically deleted according to the monthly rule;
In the last "n" months, a full backup is kept every month. When the set number of months is exceeded, the old backup will be automatically deleted.
- Incremental Backup: In the last "n" days, all backups are kept every day. When the set number of days is exceeded, the old backups will be automatically deleted according to the weekly rule;
In the last "n" weeks, all full backups will be kept every week. When the set number of weeks is exceeded, the old backups will be automatically deleted according to the monthly rule;
In the last "n" recent months, keep a full backup every month. When the set number of months is exceeded, the old backup will be automatically deleted.
- Differential Backup: In the last "n" days, keep all backups. When the set number of days is exceeded, the old backups will be automatically deleted according to the weekly rule;
In the last "n" weeks, all full backups will be kept every week, and when the set number of weeks is exceeded, the old ones will be automatically deleted according to the monthly rule;
In the last "n" months, a full backup is kept every month. When the set number of months is exceeded, the old backup will be automatically deleted.
4). By space
When the backup exceeds one group and the space is insufficient, the old backups will be automatically deleted until enough space is available to store the new backups. Only differential backup supports backup cleanup by space.
A backup group includes a full backup and several differential backups. The program will first delete the differential backups one by one in a backup group, and then delete the full backup of the group.
Written in the end
That's all about backup retention policy best practices and how to perform this policy step by step. If you are suffering from the insufficient disk space problem, you could consider using AOMEI Backupper Professional to delete old backups automatically while retaining the latest backups.
And it supports all the backup solutions and backup features, such as system backup, disk backup, incremental backup, daily backup, compression, encryption, email notification, event triggers, USB plug in, etc. No matter you want to protect your computer continuously or manage backup disk space, you could use this software. Don't hesitate, please download it to have a try.