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The 3-2-1 backup strategy safeguards organizations against data loss and costly downtime. It provides data protection in the event of a major system failure, or a catastrophic event like a fire or natural disaster.

Execution of 3-2-1 backup is simple: keep three copies of data stored on two different forms of media—disk, tape, optical, or cloud backup—with one copy stored in a remote location. Schedule backups and test backup systems on a regular basis.

Keep one backup on-premises for quick restoration; store other backup media far enough so that a destructive storm cannot damage both copies.


The 3-2-1 backup strategy safeguards organizations against data loss and costly downtime.

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Equipment for implementing a 3-2-1 backup strategy

The main piece for many 3-2-1 backup scenarios is a network attached storage (NAS) device or a shared file server. A NAS sits on the network and stores data shared by user endpoints on hard disk drives (HDDs). A basic office network setup—modem, router, switch, Ethernet cables, Wi-Fi—connects endpoints to the NAS.

A NAS or file server utilizes several HDDs in a RAID configuration. This provides disk redundancy which keeps the production copy up and running in the event of drive failure. Setting up a NAS with a RAID configuration is not the same as making a backup. You must export a copy of the NAS data onto a separate storage medium for it to constitute a backup by definition; if the NAS array were to fail or be destroyed in a fire, you would lose data without a separate backup copy to restore.

Most NAS devices have built in backup software that supports multiple types of data transfers. For example, a Synology NAS can copy files to local storage over a LAN or to external hard drives via USB 3.0; it has its own cloud storage (Cloud Station) that syncs shared files over a WAN, and supports third party cloud backup services.

Which hard drives fit the 3-2-1 backup strategy?

Disk backups are usually made to archive HDDs that provide low cost storage for large volumes of data. Western Digital’s WD Red drives are made specifically for NAS HDD configurations as well. Most small and medium size NAS storage setups conduct file transfers through a SATA interface.

The SAS interface connects enterprise file servers with enterprise HDDs. SAS offers faster data transfers at a premium price. The production copy benefits from the performance boost; however for backups at this scale, magnetic tape backup is often the most cost-effective medium for enterprise backup.

Tape drives interface via SAS to enterprise servers, and copy data volumes to tape media cartridges. LTO-7 drives and tapes are the latest generation of high performance tape media for backups.

Tape Backup Day Meme

More 3-2-1 backup resources

The Complete Guide to Computer Backup by Backblaze provides a great starting point to learn data backup basics. It dissects the pros and cons of each type of backup media by level of complexity and reliability factors.

The US Small Business Administration has guidelines that lay out a 3-2-1 backup strategy and other approaches that a small business can take to thwart data loss.

The reputable Tom’s Guide gives in-depth reviews and rates the 5 best cloud backup providers in 2016. Here’s the TL;DR version:

  1. Crashplan (9/10)
  2. Backblaze (8/10)
  3. iDrive (7/10)
  4. Acronis True Image (6/10)
  5. Carbonite (5/10)

Final thoughts

Every organization needs to protect its data from human error, system failure, and natural disasters. When properly executed—the backups occur regularly and the equipment is periodically tested—the 3-2-1 backup strategy provides a simple template rooted in data loss prevention best practices.

3-2-1 Backup Strategy Best Practices [Infographic]
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3-2-1 Backup Strategy Best Practices [Infographic]
Visual guide to the 3-2-1 backup strategy that prevents data loss and costly downtime in natural disaster and system failure scenarios.
Adam Lovinus

Author Adam Lovinus

A tech writer and Raspberry Pi enthusiast from Orange County, California.

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