A lot has changed since the 3-2-1 backup rule was first introduced in the late aughts. Unlike most things in technology, the rule has held up over the years. It’s still the de facto standard for keeping your data safe. But some of the particular best practices have evolved as data storage has changed.
The 3-2-1 backup rule is a simple, effective strategy for keeping your data safe. It advises that you keep three copies of your data on two different media with one copy off-site. Let’s break that down:
- Three copies of your data: Your three copies include your original or production data plus two more copies.
- On two different media: You should store your data on two different forms of media. This means something different today than it did in the late 2000s. I’ll talk a little more about this in a bit.
- One copy off-site: You should keep one copy of your data off-site in a remote location, ideally more than a few miles away from your other two copies.
If you want to protect your personal information, photos, work files, or other important data, the 3-2-1 backup strategy is the way to go. It helps you avoid having a single point of failure that’s vulnerable to human error, hard drive crashes, theft, natural disasters, or ransomware.
Let’s say you took a picture of your social security card for your tax accountant years ago—that file is called “socialsecurity.jpg” and it lives on your computer at home. That’s the first “copy” of your data.
You also have an external hard drive at home, used to back up your go-to Mac or gaming PC. That external hard drive will back up socialsecurity.jpg as part of its backup process. That’s a second copy on a different device or medium.
In addition to that external hard drive, you also have an online backup solution. The online backup continuously scans your computer and uploads your data to the cloud (which, in layman’s terms, is an off-site data center). Socialsecurity.jpg is included in this upload, becoming the third copy of your data.
Oh! And, your paper social security card is hopefully stored in a fire-proof safe (not your wallet) as a bonus.
If you back up your home computer to an external hard drive and back both of those devices up to the cloud using something like Backblaze Computer Backup, congratulations: You have achieved a 3-2-1 backup.
- You have three copies of your data: One on your computer, one on your hard drive, and one in the cloud.
- You store your data on two different devices: Your computer and your external hard drive. (Technically, three devices, since your data is also stored in the cloud).
- One of those copies is off-site: The cloud copy.