Own a drive, rent a cloud, and trust neither alone

Quick answer: Do both. Keep one external drive that backs up automatically at home, and one cloud service that backs up automatically from anywhere. Store the drive away from the computer it protects, and restore one file a year to prove it all works.

Most people pick a side and defend it like a ball team. The drive guys say they don't trust a company with their family photos. The cloud guys say a drive in a drawer is a dead drive waiting to happen.

Both are right about the other one. That's the whole argument for using both.

What each one actually protects you from

An external drive beats almost every problem that involves your computer. A dead laptop, a stolen phone, a spilled coffee, a bad update. You plug it in, you copy it back, and you're done in an afternoon. It doesn't care whether your internet is up. It doesn't care whether a company changes its terms, raises its price or disappears. You own it, which is a good feeling and a fair instinct for anyone who believes in keeping what's yours in your own hands.

What a drive can't survive is whatever happens to your house. A fire takes the computer and the drive sitting next to it. So does a burglary, a flood, or a toddler with a sippy cup. Drives also just wear out. A portable drive that gets knocked off a desk while running is a coin flip.

The cloud has the opposite profile. It's somewhere else, so your house burning down doesn't touch it. But it's a service, and services have strings.

• Your account gets locked, hacked or flagged by mistake, and the support line is a form.
• The card on file expires. The emails go to an address you quit using. A year later the files are gone.
• Restoring a few terabytes over home internet can take days.

None of those are likely on any given Tuesday. All of them are real. Put the two side by side and each one covers the other's blind spot.

Sync isn't backup

This is the mistake that costs people the most. Dropbox, Google Drive and iCloud Drive are built to mirror your files. Change something on your laptop and it changes everywhere. Delete a folder and it's deleted everywhere, quickly and efficiently.

Picture a guy cleaning up his desktop at 11 p.m. He drags an old project folder to the trash, empties it, goes to bed. Every device he owns agrees with him by morning. That's not a backup. That's a very fast way to be wrong in four places at once.

A real backup keeps history. Look for "version history" or "recover deleted files" in your cloud service's settings and see how many days it holds on to things. Thirty days is common. Then pick a service whose job is backup, not just syncing, for the files you can't replace. Your existing phone backup might already do it, and the piece on backing up everything so a lost phone is just a bad afternoon covers that side.

The same goes for ransomware. If a file is locked by a bad actor and your drive stays plugged in, the drive can get scrambled right along with the computer. Which brings us to the setup.

The setup, in order

1. Buy the drive. Get a portable drive at least twice the size of what you're protecting. If your computer holds 500 GB, buy 1 TB or more. Drives fill up, and your backup needs room for older versions. A spinning drive costs less per terabyte. A solid-state one survives a drop better. For a drive that lives in a drawer, either works. If it rides in a bag, spend the extra on solid-state.

2. Turn on the built-in tool. Macs have Time Machine. Windows has File History and a backup app. Plug the drive in, point the tool at it, and let it run. Don't build a clever system of your own. The boring one that runs by itself is the one that's still running in three years.

3. Pick the cloud service. Any reputable service that backs up automatically will do. Choose by what it holds on to, how long it keeps deleted files, and whether you'll actually read the billing emails. Use a long, unique password and turn on two-step verification before you upload a single file. The evening lockdown of your accounts is worth doing first, because the cloud is only as safe as the login in front of it.

4. Move the drive. This is the step people skip. A backup that sits next to the computer is just a second thing to lose in the same fire. Keep it in a drawer at your office, at your parents' place, or in a fireproof box bolted down in the house. Better still, buy two drives and swap them every month or two. One's home. One's away.

5. Restore something. Once a year, pick a random file and pull it back from both the drive and the cloud. Open it. If it won't open, you've just found out in the cheapest way available.

The annoying parts

The first cloud upload is slow. Really slow. A big photo and video library can take days or weeks on a typical home connection, because upload speeds run far below download speeds. Leave the computer on, let it chew, and don't judge the service by the first week. The piece on home internet numbers that matter explains why the upload number is the one to check.

If you shoot a lot of video, the cloud bill grows with your library. You don't have to put every raw clip up there. Cloud-back the irreplaceable stuff (family photos, tax records, documents, anything you made yourself) and let the drive carry the bulk.

Drives also die quietly. If the backup tool says it hasn't finished in two weeks, that's not a glitch to ignore. Look at it.

When one is enough

Be honest about your situation. If you've got a phone, a laptop with mostly documents, and a modest photo library, a good automatic cloud backup with version history is a sensible minimum. It beats nothing by a mile.

If you're offline a lot, you've got a huge library, or you simply don't want your files living on someone else's server, a drive plus a second drive kept off-site is a legitimate plan. It takes more discipline and it's cheaper over time.

What isn't a plan is one copy on the computer and one in a drawer beside it. Or one cloud account and the hope that nobody ever locks it. For the pictures you'd grieve over, the rule of three copies of every photo you'd grieve losing still holds. Two kinds of storage, one of them somewhere else.

Leave it better than you found it

Next time you visit your folks, ask your dad when his computer was last backed up. Odds are he'll go quiet. Bring a drive with you, set it up before dinner, and show him the one light that means it's working. Put your mom's phone on a cloud backup while you're at it. It takes about an hour.

Then go home and run the test on your own gear. Pick a file and pretend your laptop fell in a lake. If you can get it back by supper, you're covered.