The 3-2-1 Backup Rule (and what it actually looks like in 2026)

3-2-1 is the simplest backup rule: 3 copies, 2 different types of storage, and 1 copy offsite. In 2026, add two modern realities: immutability (so ransomware can’t encrypt your backups) and testing (so you know you can restore).

Server racks

One practical example:

  • Primary: production (what you’re protecting)
  • Local backup: repo on a NAS or backup appliance
  • Offsite: object storage (cloud) with immutability / versioning

Quick sanity check:

  • RPO documented (how much data you can lose)
  • RTO documented (how fast you must recover)
  • Restore test run recently

Image: Unsplash

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