December 11, 2021

Backup Strategy: What is the 3-2-1 backup rule?

By George Rouse
Backup & Recovery

What is the 3-2-1 Backup Rule?

The 3-2-1 backup rule states that you should have 3 copies of your data, 2 different backup formats, and 1 backup stored offsite. This rule was first established by U.S. photographer Peter Krogh in the early 2000’s and has gone on to stand the test of time and is still relevant today.

Backup Vs Business Continuity & Disaster Recovery (BCDR)

However as variations of this rule have developed and businesses try to ensure a more resilient data model, the rule has become just 1 part of an overall protection plan. Most businesses now create and deploy a BCDR or Business Continuity & Disaster Recovery Plan which not only ensures reliable backups of data but also focuses on time of recovery.

Why Use the 3-2-1 Backup Strategy?

The 3-2-1 rule still has value, especially for businesses who aren’t backing up at all. But today, the gold standard is evolving. As businesses develop, most will partner with an MSP or Managed Service Provider to ensure that their IT infrastructure runs smoothly.

One of the key parts of a managed service is to prepare for downtime or a disaster event. The idea of 3-2-1 backup rule is to protect against a single disaster such as a fire or flood in the office, in this situation you would be able to recover from your offsite backup.

However over the years where threats have become more aggressive and reliance on IT grows this rule is no longer enough.

Variations of the 3-2-1 Strategy

Over the years there have been multiple variations of the 3-2-1 rule such as 3-2-1-1-0 and 4-3-2 however these have their own range of issues including costs and time to manage the infrastructure that goes with these strategies.


3-2-1-1-0 is built on the same foundation as the 3-2-1 rule however it goes a step further by stipulating an additional “Air Gapped” or offline backup and adding a check process to ensure all backups have zero errors.


Suggests that for businesses being managed by MSPs or IT Service Providers you have 4 copies of your data, stored across three locations (Onsite as source, onsite with the MSP and one in the cloud), with two of these being offsite.

Drive efficiency with an automated BCDR Solution – Datto SIRIS

Datto is one of the pioneers of the All-in-one BCDR solution that removes a lot of manual setup, expensive cost and human error in handling different media types across multiple locations.

Datto SIRIS is a flexible BCDR solution that stores a copy of your data locally, and in our cloud that’s built on an immutable storage model, you also have the ability to replicate that data to a secondary datto cloud location for extra resilience.

With our end to end backup encryption, advanced backup verification and mandatory 2FA sign on to access backup data and recover (both locally and from the cloud) you can be confident that your backups are secure and ready for when you need them.


Suggested Next Reads