3-2-1 backup: the rule that protects your data

A failed disk. A stolen computer. Ransomware. A file deleted by mistake. In all these cases, only one thing matters : do you have a backup that works ? The 3-2-1 rule is the simplest and most solid answer. Here is what it means.

The 3-2-1 rule in one sentence

Keep three copies of your data, on two types of media, with one copy off-site.

Three copies

Your original data, plus two backups. If one copy is lost or corrupted, you still have two. A single backup is never enough.

Two different media

Do not put all your copies in the same place. For example an internal disk and an external disk. Or a server and the cloud. If one type of media fails, the other holds.

One copy off-site

At least one copy must sit somewhere other than your premises. A fire, a flood or a theft takes everything that is on site. The cloud, or a disk kept remotely, protects against that.

Why this rule works

It covers the three most common risks. Hardware failure. Human error. Disaster or theft. Each level of the rule answers one of these risks. It is easy to remember and hard to catch out.

The most common mistake

Many companies have a backup, but have never tested it. On the day of the problem, they find out the backup is incomplete, too old, or unreadable. A backup you have never restored is not a real backup. Test a restore at least twice a year.

How often should you back up?

The right frequency depends on what you can afford to lose. Ask yourself a simple question. If you lose today's work, is that serious ? For most SMBs, one backup a day is the minimum. For data that changes all the time, like accounting or orders, aim for several times a day. What never changes can be backed up less often.

How to apply it in an SMB

A few concrete steps.

1. List what is truly vital : accounting, customer files, emails, production documents.
2. Choose two media. For example a local NAS and a cloud space.
3. Automate the backups. A manual task always ends up forgotten.
4. Check that the off-site copy really leaves, every day or every week.
5. Test a restore, and note the date.

And is the cloud enough?

The cloud is an excellent off-site copy. But a single copy in the cloud does not follow the 3-2-1 rule. Keep a local copy too, faster to restore. And check what your provider actually backs up. Many cloud services do not keep your data as long as you think.

Not sure about your backups? We can check them and set them up. Explore our infrastructure and hardware, or get in touch.