3-2-1 Backup Rule

Simple definition

A backup rule recommending three copies of data, on two types of media, including one off-site.

Technical definition

Model 32-1 reduces the risk that a single incident will simultaneously destroy all available copies.

What is it used for ?

Build a more fault-resistant, sinister and ransomware-resistant backup strategy.

Practical example

Production data can be copied to local storage and then replicated to a separate cloud.

Common issues

• all connected to the same domain
• Offsite never tested
• Local backups only

Related terms

Backup · Unchangeable backup · Air gap

Key takeaway: This entry explains the general operation of the term. Exact settings may vary depending on software, vendors and environments.