3-2-1 Backup: What It Really Means

The 3-2-1 backup approach is a simple way to think about resilience: keep three copies of important data, use two different types of storage, and keep one copy offsite.

The numbers are a starting point

The value is not the numbers by themselves. The strategy is designed to reduce the chance that one event destroys every copy.

Different storage matters

If all copies depend on the same device or failure domain, they may fail together.

Offsite matters

The offsite copy helps protect against events such as theft, fire or a larger local failure.

Recovery still matters

A backup that cannot be restored is not a useful backup. Test recovery of important information and know how long recovery would take.

Make the strategy fit the data

Not every file has the same value. Identify what would be difficult or impossible to recreate and protect it accordingly.