SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/secplus-differential-backup

To restore from differential backups, which backup sets do you need?

The last full backup plus the most recent differential backup.

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  1. Every incremental since the last full
  2. Only the most recent differential
  3. The full backup and the latest differential ✔

Why: A differential backup copies everything changed since the last full backup. So restoring needs only the full backup plus the last differential. Incrementals need the whole chain, which is slower to restore.

Huh, didn't know that: Differentials take longer to create each day because the data since the last full keeps growing.

The dad joke
My differential backup and I have one thing in common: we both keep piling up until Sunday's full reset.
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References

Answer: The full backup and the latest differential. A differential backup copies everything changed since the last full backup. So restoring needs only the full backup plus the last differential. Incrementals need the whole chain, which is slower to restore.

  1. NIST SP 800-34 Rev. 1, Contingency Planning Guide for Federal Information Systems nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-34r1.pdf
    only the full backup media and the last differential media would be needed
    Checked 2026-10-10.

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