Dell NetWorker 19.9 Administration Guide

Synthetic full backups

A synthetic full backup combines a full backup and subsequent incremental backups to form a new full backup. A synthetic full is equivalent to a traditional full backup and can be used in all the same ways as a traditional full backup.

A synthetic full save set includes data that was backed up between the full backup and the last incremental backup. After a synthetic full backup occurs, the next synthetic full backup includes data that was backed up between the previous synthetic full backup, and subsequent incremental backups.

During a traditional full backup, client data is sent over the network to the NetWorker storage nodes, which can have a negative effect on client network performance. For synthetic full backups, however, the NetWorker software analyzes the full backup and subsequent incremental backups, extracts the most current versions of files, and then streams the data into a new full backup. Synthesizing the new full backup does not include the client machines and localizes the network traffic to the NetWorker server and storage nodes.

Performing synthetic full backups also reduces recovery time because the data is restored from the single synthetic full backup instead of from the last full backup and the incremental backups that follow it.

Synthetic full backups do not eliminate the requirement for full backups. It is recommended to perform full backups on a monthly or quarterly basis, and limit the number of incremental backups.