Differential and Incremental Backups

The purpose of both incremental and differential backups is to optimize the amount of data being transferred during subsequent backups of resources that change over time. Once you perform the base backup for a resource, which typically involves significant quantities of data, instead of transferring the entire resource again to a backup destination, you only need to transfer the part that has changed or has been added.

The common features of incremental and differential backup are as follows:

1. Both backup types only back up the data that has changed since the last backup.

2. They both require a base backup to be performed before they can be executed successfully.

3. Incremental and differential backups can be scheduled at different intervals and have different output destinations.

4. Both backup types help reduce the amount of data that needs to be backed up and stored, compared to a full backup.

The difference between incremental and differential backup is as follows:

• Incremental backup: It backs up selected files that have changed since the previous backup (base, incremental, or differential) with the same name. It takes the shortest time, minimizes media volumes required, and has a minimal effect on the catalog. However, it increases the number of media volumes required to restore during disaster recovery.

• Differential backup: It backs up all selected files that have changed since the last base backup of the same name. It is a compromise between base and incremental backups, providing some of the advantages and disadvantages of each. It requires fewer media volumes to restore during disaster recovery compared to incremental backup, but it takes longer than incremental backup.

It is up to the user to choose the best solution for them.