Incremental vs Differential Backup – Datto

The main difference between incremental and differential backups is how they save space and time by storing only the changed files. However, the efficiency of incremental backups is very different from differential backups.

Before we dive into the differences between incremental and differential backups, let’s review full backups.

Still using full backups?

In its simplest form, a full backup is the starting point for incremental and differential backup strategies. A full backup, of course, backs up all data on a partition or disk by copying all sectors of the disk with data to the backup image file.

A full backup is time-consuming and space-intensive, usually used as part of a backup plan with long intervals, such as once a week or a month. During this time, if something goes wrong, a lot of data can be lost. That’s when these two backup strategies come into play.

An average partition or disk only contains a small number of changes per day, or even per week. Therefore, it only makes sense to back up data that has changed on a daily basis. This is the foundation of smart backup strategies.

Incremental vs differential backup: How do they compare?

Differential and incremental backups are different backup strategies with the same purpose: to optimize backup time and space. Differential backups only back up files that have changed since the previous full backup, while incremental backups do the same, backing up files that have changed since the previous incremental or full backup.

Datto SIRIS ensures reliable backups with our backchain technology™ with fundamental changes to the way backup and recovery is performed, allowing each incremental snapshot to be a fully constructed recovery point.

Learn more about Datto SIRIS

What is

differential backup? The differential backup strategy

performs daily backups of files and folders that have changed since the last full backup. They are much faster than full backups as less data is backed up.

One of the

benefits of this strategy over incremental backup is that you only need the last full backup and the last differential backup to restore the data, which makes the restore process much faster. However, the amount of space consumed by the backup data will increase with each differential backup until the next full backup.

Although differential backups

are more flexible than full backups, they still present too many obstacles to routine use, especially as the next full backup approaches.

Diagram showing how

differential backups work What is incremental backup? Unlike differential backups, incremental backups changed files from the last backup of any type, which can be a full backup or an

incremental backup

. When performing incremental backups, the shorter the time interval between backups, the less data is needed to perform backups.

It is the strategy with the highest space efficiency among the three: complete, differential and incremental.

Although incremental backups

provide greater flexibility and granularity (time between backups), they have a reputation for taking longer to restore because they must be built from the last full backup and all subsequent incremental backups. Datto has developed the reverse chain technology™ that uses the best of all these backup strategies.

Smart backup


back-chain technology Datto’s back-chain technology

ensures you can quickly and reliably back up and recover your data in no time

. This is based on this traditional incremental backup, however,

Datto uses ZFS to make each incremental point refer to all other points in the chain, therefore only one full backup should be stored.

This increases the redundancy of backup chains and flexibility in how each point is stored and used to virtualize a system in a Disaster recovery scenario.

Talk to our sales team about Datto SIRIS and our reverse chain technology today