Choosing Full, Differential, Or Incremental Backups
Backups are divided into three types:
- Full: The first backup of a system, capturing everything in it. The upside of a full backup is that it’s self-contained. The downside is that it takes up a lot of space, can take a long time to complete, and can be almost identical to a previous full backup.
- Differential: A backup that captures only the differences between the current state and the last full backup. Recovering from a differential backup requires both the last full backup and the differential backup to be valid. The upside of a differential backup is that it’s much faster than a full backup. The downside is that it takes up more space than an incremental backup and requires at least two backup files to be read for recovery.
- Incremental: A backup that captures only the differences between the current state and the last differential, incremental, or full backup. The upside of an incremental backup is that it’s very small and very fast. The downside is that recovering with an incremental backup requires all the data from the last full backup and every successive incremental backup until the recovery-point objective to be valid and read. As a result, recovery with this type of backup can be time-consuming.