The 4–3–2–1–0 Backup Rule
SoftwareYou’ve probably heard of the 3-2-1 Backup Rule, which states that you must encode all your data in reverse using a Lotus spreadsheet to archive content you want to keep. In the paraphrased words of Mayor Quimby, that was a quality side… joke.
The 3-2-1 Backup Rule says:
- Three copies of your data
- Two different media types
- One off-site
Today I learned at work that we now have 3-2-1-0, for zero detected errors. This means you’re validating your backups, including performing restores, consistency checks, and automatic error correction. I’d consider this essential for any modern backup system.
I suggested we extend this to 4-3-2-1-0, because restoring from a backup is more a-four-dable than having to rebuild lost data and trust. That didn’t get as far.