3-2-1 backups

Data volume → copy capacity by the 3-2-1 rule

Parameters

3-2-1 rule: at least 3 copies of data, on 2 different media, 1 off-site/cloud. Add versioning (ransomware encrypts backups on the same disk too) and an offline/immutable copy. Test restores — an untested backup isn't a backup.

Capacity

Primary
500 ГБ
Local backup (with versions)
535 ГБ
Off-site copy
535 ГБ
Total capacity
1570 ГБ
In a year (growth)
1875 ГБ

3-2-1 checklist

  • 3 copies: original + 2 backups
  • 2 media: NAS disk + cloud/external drive
  • 1 off-site copy: cloud or drive elsewhere
  • Versioning: at least 7 restore points
  • Immutable/offline copy against ransomware
  • Restore test quarterly
  • Encrypt backups (especially off-site)
  • Automation + error monitoring