Keep 3 copies of anything you'd hate to lose, on 2 different kinds of storage, with 1 copy somewhere else (off-site or in the cloud). Then check now and then that you can actually get your files back.
Why bother?
Drives fail. Laptops get dropped, stolen or left in an Uber. Files get deleted by accident. Ransomware can lock up everything a computer can reach. A good backup turns all of those from a disaster into an inconvenience.
The rule, one number at a time
3 copies
Your original, plus two backups. If one copy fails, you still have another.
2 different kinds of storage
For example, your computer's drive plus an external drive, or your computer plus a cloud backup service. Different kinds of storage are less likely to fail at the same time.
1 copy off-site
If there's a fire, flood or break-in, a backup sitting next to the computer goes too. Keep one copy somewhere else, and a cloud backup service is the easiest way to do that.
What that can look like
- At home: your computer, plus an automatic backup to an external drive (Time Machine on a Mac, File History or a similar tool on Windows), plus a cloud backup service.
- For phones: turn on iCloud Backup (iPhone) or Google One backup (Android), and keep important photos in a second place too.
- For a business: managed backups of computers, servers and cloud apps like Microsoft 365, with at least one copy that can't be changed or deleted by an attacker, and regular test restores.
The part everyone skips: test it
A backup you've never restored from is a hope, not a plan. Every few months, try getting back one file or folder. It takes minutes and tells you the backup really works.
Try this today
- Pick the one folder you'd be most upset to lose (usually photos).
- Count how many copies of it exist and where. Is one of them off-site?
- Restore a single file from your backup to prove it works.