The 3-2-1 rule is a decade out of date. If you're still quoting it, you're behind.

The 3-2-1 rule is a decade out of date. If you're still quoting it, you're behind.

3-2-1 was written before ransomware specifically hunted backups. The modern rule is 3-2-1-1-0: three copies, two media, one offsite, ONE immutable or air-gapped, and ZERO errors on a tested restore.

— 3-2-1: assumes accidents, not attackers
— 3-2-1-1-0: assumes someone is trying to kill your backups

The extra '1-0' is the whole point now. Quoting plain 3-2-1 in 2026 is quoting a museum piece. Fight me in the comments.