Difference Between Differential Backup and Incremental Backup
By Tobias Geisler Mesevage
Differential and incremental backups are different backup strategies with the same purpose: optimize backup time and space.
A full backup is the simplest form of backup, and both strategies require a full backup as a starting point. A full backup is time-consuming and requires a lot of space, it’s usually done by backup plans between long intervals, like once a week or a month. During this time, if anything goes wrong, a lot of data can be lost. That’s when these two backup strategies come in hand.
Differential Backup: quicker to restore, but requires more space
Differential backup strategy backs up files and folders that have changed since the last full backup, on a daily basis. They are much quicker than full backups since less data is being backed up.
One of the benefits of this strategy over incremental backup is that you only need the last full backup and last differential backup to restore data, making the restoration process much faster. However, the amount of space consumed by backed up data will grow with each differential backup until the next full backup.
Incremental Backup: slower to restore, but more space-efficient
Unlike differential backups, incremental backup copies changed files since the last backup of any type, which can be a full backup or an incremental backup.
It’s the strategy with the most space efficiency between the three: full, differential, and incremental.
However, the restoration process is usually slower than other strategies, since the backup has to be reconstituted from the last full backup plus all the incremental backups to restore data.