3-2-1 Backup Rule: Simple Backup Setup for Home or Office

The laptop won't start, and the invoices, tax files and family photos lived only on it. Some recipes don't need a stove. This one needs two places to keep copies and an afternoon.

Here is the "3-2-1 rule" as a recipe: three copies of your files, on two kinds of storage, with one kept somewhere else.

Recipe card

• Dish: Slow-cooked 3-2-1 backup
• Serves: one home office, or a small back office
• Prep time: one afternoon, then it mostly cooks itself
• Difficulty: easy. Harder than restarting a router. Easier than losing six years of records.

Headnote: if you only have one copy of your files, you don't have a backup. You have a risk.

Ingredients

• 1 original copy: the files on your computer, as they are now.
• 1 local copy: an external drive or a "NAS," which in plain English is a small file box on your office network.
• 1 off-site copy: a cloud backup service, or a second drive that lives at another address.
• 1 backup app, built in: File History on Windows, Time Machine on a Mac.
• A pinch of labels: drive name, what's on it, the date you set it up.

Method

1. Prep the list. Write down what you can't lose: documents, photos, accounting files, email archives.
2. Season the local copy. Plug in the drive and turn on the built-in app. Time Machine keeps hourly, daily and weekly backups. File History covers Documents, Pictures, Videos and Desktop to start.
3. Layer on the off-site copy. Point a cloud backup at the same folders. Now one fire, flood or theft can't take everything.
4. Unplug and rest. Disconnect the external drive when the backup finishes. A copy that isn't connected can't be scrambled by ransomware.
5. Taste-test. Restore one file to a new folder and open it. A backup you've never restored is a guess.

Chef's notes

Hidden tip: a synced folder is not a backup. "Sync" means every device holds the same thing. Delete a file you only keep in OneDrive's cloud and Microsoft says it's gone from your OneDrive on every device and online. A real backup keeps older versions.

Hidden tip: your safety net has a timer. Files deleted from OneDrive sit in its recycle bin for 30 days on a personal account, 93 days on a work or school account. After that, you need a backup.

If your backup turns out stale, you probably left the drive in a drawer for months. Next time, put "back up and unplug" on a recurring reminder.

Variation: for a busier office, swap the external drive for a NAS so several computers back up to one place.

Plenty of my clients learned this one the hard way. My cast-iron skillet gets more regular care than most office files.

Serving suggestion

Practice restoring files at least every few months, and plate the result on a sticky note: what's backed up, where, and when you last tested it. Best served boring.

Cheat sheet: the 3-2-1 backup

Clean-up: label the drive, unplug it, and close the ticket.