Data security: backup and the 3-2-1-0 rule

13 June, 2022

Stefano Papaleo

Stefano Papaleo
CTO | PM & Solution Architect | Team Leader dell’area Service Delivery


The experience of data loss is a traumatic event, both in the private sphere and, even more, in the corporate context. In the latter case, the event can constitute a major damage both for the organization and for its customers and suppliers. To prevent it, there are best practices that need the right methods of application in order to be reliable.

Why it is important to have a Disaster Recovery Plan?


A loss of corporate data, whether due to a failure, an environmental disaster, a fire, or a hacker attack (such as ransomware), is a real disaster for the organization, with an operational stop that very often results in a collapse of reputation and turnover.

That's why, whatever virtual environment your company uses (Vmware, Hyper-V or other), is critical to have a backup of data available. In fact, being able to rely on a reliable recovery point is the only way to perform an effective disaster recovery that will allow the company to return immediately to operation without consequences.

For this to happen in complete safety and efficiency, companies should follow a good backup policy, called till few time ago the "3-2-1 rule" and now evolved, thanks to Veeam Backup & Replication, into the "3-2-1-0 rule."

3-2-1-1-0 backup rule: what is it?

The original "3-2-1-1 rule" was based on a very simple principle regarding the storage of data:


  • possess at least 3 copies (also called the "rule of 3")
  • keep the copies on 2 different media
  • keep off-site 1 of the copies


The expression "3 copies" means that, in addition to the original, it is necessary to have at least two additional backups. In this way the risk of failing at the same time decreases exponentially, reaching, in the case of one original and two copies, the 1-in-a-million chance index.

All this is valid if there are no common causes of failure, which could happen if all copies were saved in the same place, as is the case, for example, with disks in the same RAID system.

In fact, having multiple copies allows each one to be stored in a different physical location, averting the danger posed by accidents such as fire, explosion, and so on.

Also according to the "3-2-1 rule," it is good to keep copies of data on two different types of storage, such as an internal and an external hard disk, possibly, as we said, stored in different locations.

Finally, 1 of the copies should always be stored off-site, so that it cannot be damaged by a concrete adverse event or be tied to a physical location.

How the 3-2-1-1-0 rule works

The "3-2-1 rule" evolves into the "3-2-1-0 rule" when applied to VMware or HyperV environments via Veeam Backup & Replication.

The second "1" that is added indicates that in addition to an off-line backup copy, an "immutable" one must be created. This type of backup allows a faster data storage, the ability to maintain information history, and most importantly, an increased security against hacker attacks such as ransomware.

The "0" that is added at the bottom, stands for "zero errors," and indicates the fact that during the automatic verification of backup recovery, Veeam's SureBackup feature ensures complete compliance and the total absence of functional bugs in the process and in the data itself.


This is possible thanks a constant monitoring of backups, which also enables the fastest correction of errors.

Veeam Backup & Replication also meets all the other parameters indicated by the "rule," for at least three reasons:


  • Thanks to the Backup Jobs feature, it allows the creation of several backups simultaneously
  • Being storage-independent, it works with all types of media, from disks to the cloud
  • Through Veeam Cloud Connect it is possible to get off-site cloud backups directly into a service provider's infrastructure

For all these reasons, applying the "3-2-1-0 rule" through Veeam is now considered a must by all those companies that want to protect their data at their best.

It is important, in order to take full advantage of its potential, to refer to a certified and trusted partner who has the expertise to best implement the right solution.


Interested in the best backup strategies to make your data more secure and want to know more? Get in touch!

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