Fundamentals
The 3-2-1 Backup Rule Explained
22 January 2026 · 5 min read
Three copies, two kinds of media, one offsite. A forty-year-old rule that still decides who recovers.
The 3-2-1 rule is the shortest useful description of a backup strategy: keep three copies of your data, on two different types of media, with one copy offsite.
Three copies
The working copy on your computer, plus two backups. Two backups sounds excessive until you discover that a backup drive has been quietly failing for six months.
Two types of media
An internal SSD and an external HDD. A NAS and cloud storage. The point is that a single failure mode — a controller fault, a bad batch of drives, a power event — should not be able to take out every copy.
One copy offsite
This is the copy that survives theft, fire and flood. For most people and small businesses in India, an automatic cloud backup is the only offsite copy that stays current without anyone remembering to do it.
Your files should survive your computer.
Nuvanta Cloud backs up your computer and external drives automatically, with version history you can roll back to.