How to use synthetic backups in place of recurring full backups

Last published : Apr 02, 2026
The synthetic backup feature eliminates the need to perform recurring full backups for supported remote resources. The synthetic backup is assembled from a full backup (called a baseline) and subsequent incremental backups.
The resulting synthetic backup then becomes the new baseline. Only incremental backups are required until the next synthetic backup is created. The synthetic backup is as current as the last incremental backup that it contains.
The components of a synthetic backup are as follows:
  • Baseline backup.
The baseline backup is the first full backup to run that is associated with the synthetic backup. The full baseline backup runs one time only, and backs up all of the files on the selected computer when it runs.
  • Recurring incremental backups.
Incremental backup jobs back up the files that change after the baseline backup.
  • Recurring synthetic backups.
The synthetic backup process combines the data from the baseline backup and the incremental backups to form a synthesized full backup of the selected computer. This synthesized full backup becomes a new baseline backup, which is combined with subsequent incremental backup sets to form a new synthesized full backup.
For any of the backups in a synthetic backup, you can add a stage to duplicate the backup data to tape.
True image restore is automatically enabled for synthetic backups. True image restore lets you restore directories as they existed at the time of the synthetic backup. Files that were deleted before the time of the synthetic backup are not restored. In true image restore, only the correct versions of files are restored from the appropriate synthetic full or incremental backups that contain them.
Only file system data is supported for synthetic backup. Supported data includes common file system objects, such as volumes, drives, and folders.
Requirements for synthetic backup
Before you create a synthetic backup, review the following information:
  • If you use an encryption key, all of the associated backups must use the same encryption key. Do not change the encryption key after the backups are created. The encryption key that is selected in the associated backups is automatically applied to the synthetic backup.
  • You must configure disk storage before you can create a synthetic backup. For synthetic backups, incremental backups must use disk storage. The baseline full backup and the synthetic full backup can use tape or disk storage.
See Configuring disk storage.
  • If you send the baseline backup job to tape storage, and you want to use tape storage for the synthetic backup job, you must have two tape drives. You must use a tape drive to mount the baseline backup, and use a tape drive to mount the synthetic backup.
  • You can select only file system data for synthetic backup.
More Information
Configuring off-host backup options for a backup job
About true image restore for synthetic backups