Backup Strategies Explained: Full, Incremental, Differential, and 3-2-1

Summary

An explainer compares full, incremental, and differential backups, describes electronic vaulting, remote journaling, and mirroring, and outlines how RPO and the 3-2-1 rule guide resilient backup planning.

Key points

• Full backups copy all data; they are simple to restore but resource-intensive.
• Incremental backups capture changes since the previous backup; restores require the last full backup and every subsequent incremental.
• Differential backups capture changes since the last full backup; restores need only that full backup and the latest differential.
• Electronic vaulting transfers bulk data offsite on a schedule, while remote journaling continuously sends transaction logs for point-in-time recovery.
• Remote mirroring maintains a live duplicate at another site and is presented as the option for a zero RPO, at higher cost.
• The 3-2-1 rule calls for three data copies, two media types, and one offsite copy.
• Backup choices should be based on RPO and RTO, and recovery plans should be tested.