The 3-2-1 Backup Rule

Jun 23, 2020

Having seen the impact of hardware/drive failures, ransomware attacks, the associated panic, followed by the realisation of the unnecessary data loss, and then the witch-hunt to find blame for said data loss … well … before any of this happens to you, perhaps it is time to review your backup strategy.

One widely used rule that can address such failure scenarios is called the 3-2-1 Backup Rule. This approach to your backups helps answer two important questions: how many backups do I have and where should I store them?

In addition to your actual servers and their associated data, you should also have at least two backups. Even a trivial event, such as a fire alarm triggering the sprinkler system could literally wash all your data away. Countless other incidents could bring about the same outcome, such as theft, fires, earthquakes etc.

Therefore, having one backup is not enough, especially if its stored in the same location and on the same type of media as the primary data.  Obviously, the more backup copies you have, the less chance you have losing them all at once. Thus, The 3-2-1 Backup Rule states that you need at least three copies of your data, meaning the primary data and two backups.

Storage devices will fail sooner or later. Disks fail over time, whether because of defects or simply just wear and tear. Two devices of the same type/make/model have a greater risk of failing around the same time than two devices or media of different types. Consider a combination of options such as external hard drives, tape, somewhere in the cloud, or network attached storage (NAS).

Obviously, a local disaster can damage all copies of your data stored in the same location. The 3-2-1 Backup Rule states you should keep at least one copy of your data in a remote location, such as offsite storage or in the cloud (like our super fast Cloud Connect offering). If you want to protect your data from disasters which may strike large areas, “remote” should mean as far away as possible, perhaps in another city or even another country.

Consider also, while storing one backup copy offsite strengthens your data security, having another backup copy onsite provides for faster and simpler recovery in case of failure.


Deano is part of vBridge's amazing infrastructure team, who are responsible for keeping the lights on, and making sure your IaaS experience is a happy and productive one.