Synthetic Backup in 2024: In-Depth Guide

Backing up your data is essential to protect your business from attacks, errors or outages. Your company’s backup approach determines your ability to restore to previous configurations, the disk space for backups and resource requirements of the backup process. By using synthetic backup and other modern backup approaches, businesses can optimize these 3 parameters:

What is synthetic backup?

Synthetic backup (or synthetic full backup) is a data backup method that synthesizes an initial full backup and subsequent incremental backups to create a new full backup. Let’s define three basic backup methods to understand what synthetic backup provides:

• Full backup is a method that involves copying the entire set of data that an organization wishes to backup.
• Incremental backup method starts with an initial full backup and then backs up only the data that have changed since the last backup, regardless of its type.
• Differential backup, similar to incremental backup, starts with an initial full backup. However, rather than backing up the changes from the last backup, it backs up the data that has changed since the last full backup every time it launched.

Synthetic backup also starts with a full backup and then creates a number of incremental backups. Then, the incremental backups are integrated into the initial full backup to obtain an up-to-date full backup. This new synthesized full backup acts as a starting point for the next iteration of the process.

What are the advantages of synthetic backup?

Synthetic backup allows creating new full backups without pulling the data in its entirety from its source. It provides renewed backups of your entire data without the storage and time requirements of making a full backup again and again.

Consider a scenario where your organization backs up its data every Monday.

• On the first Monday, a full backup is made. While it would be convenient to have full backups for every week for data recovery purposes, copying the entire set of data every week requires significant amounts of storage space, bandwidth, and time.
• Incremental and differential backup methods help mitigate this problem. Instead of copying the entire set of data every week, incremental backup method backs up only the changes made since last week while differential backup method backs up the changes since the first Monday (the last full backup). 

The downside with these two methods is that if you want to recover a specific file at some point, you need to inspect the initial full backup and the other smaller backups which can be time consuming or inconvenient depending on the software implementation.

Now, let’s say you have your initial full backup and incremental backups for the last three Mondays. With synthetic backup method, you can combine these four backups into a new full backup that contains all the changes made during the month. It saves storage space because it overwrites old backups. It saves time because it provides a full backup without actually copying the entire dataset once every month.

What are the disadvantages of synthetic backup?

The downside of synthetic backup is that it overwrites existing backups when it combines them. So it saves storage space and time but it is not possible to access several different versions of a file.

What are the alternatives to synthetic backup?

Synthetic backup is not the only advanced backup option. Here are some alternatives:

• Reverse incremental backup is a method similar to synthetic backup. Starting with a full backup, the subsequent incremental backups are immediately injected into the full backup. In contrast to synthetic backup, it also stores incremental backups so it provides access to different versions of the same data.
• Forever incremental backup also starts with a full backup. Then, it performs incremental backups indefinitely and keeps deleting old incremental backups after a specified time interval.
• Continuous backup method backs up every change in the source data whenever a change is made.

A modern backup solution should provide some of these advanced backup options on top of the three basic methods. Forrester advises enterprises to avoid backup products that do not provide advanced backup methods such as synthetic backup or forever incremental backup.

If you are looking for backup solutions, you can search our data-driven, transparent list of backup software.

If you are ready to contact backup technology vendors who can provide solutions like synthetic backups, let us know so we can help you: