Back up what you can’t replace, then prove it opens

Every hard drive, phone and memory card you own will fail one day, and the day is not announced. Many people say it the same way — do not wait for a failure, because failure is certain and sudden — and one person warns a failing drive may give as little as twenty seconds’ warning. You probably already know you should do this. What follows is how to start small enough that you actually do.

Keep at least three copies of anything you cannot replace, on at least two different kinds of storage, with one copy outside your home — and open a file from the backup now and then to prove it works.

Start with one folder, today

You do not need to back up everything, and you do not need special equipment to begin. One person says to sort what you have into three piles: the irreplaceable (family photos, your own writing, scanned documents), the nice to have, and what you could download again, like films and games. Back up the first pile first. One says to know what matters to you and where it actually lives on your devices; another, to know how much of it there is before you choose where to put it.

Then copy it. One person says that if you are not technical, opening the folder and copying the whole thing to an external drive is good enough, with no special software. One says a backup does not have to be complicated — the same files saved in two different physical places already counts. One suggests emailing important documents to yourself, which gives you a free, searchable second copy in a different place. And one warning is a good test of where you stand: if you do not know when your last backup was, it has been too long.

If everything you own could be downloaded again, one person says backing up is wasted effort, and others answer that even replaceable things take time to rebuild, and that irreplaceable things — photos, original work, documents — do exist. The decider they give is whether you have anything truly irreplaceable. If you do not, this page is not for you. One person describes people keeping decades of photos with no physical copy anywhere; that is the person it is for.

Then build to three copies

The rule is called 3-2-1, and many people give it. The US government’s own backup guidance states it the same way: keep three copies of any important file — the original and two backups — on two different types of storage, so that one kind of failure cannot take both, and keep one copy away from your home. Some people put the idea as a saying: a file with no backup does not really exist, one with a single copy is barely backed up, and none of it is safe until a copy lives somewhere else.

The “somewhere else” is the part that is easy to skip. Some people say a backup in the same house is not enough, because a fire, a flood or a burglary takes the computer and the drive beside it together. One copy has to live away from the main device. Some people say a drive kept at a trusted friend’s or relative’s house works, if it is kept safely there. One person suggests keeping an external drive in a bank safe-deposit box, and one person warns a spinning hard drive left unused for a long time, as in a safe-deposit box, can seize up — so bring it home now and then, update it and check it. Some people say an external drive kept unplugged, or in a secure place, is a backup that does not depend on the internet at all, and they prefer solid-state drives to spinning ones; either kind is worth plugging in and checking now and then, because neither is made to sit unpowered for years.

How much is enough? One person says that for most people, a single cloud copy plus a single drive copy is plenty, because losing all three copies at once is unlikely. One person thought 3-2-1 might be overkill for a household and could scare people off backing up at all; elsewhere, the answer to the same doubt was that drives do die and one backup is not enough. Some people add that drives fail even sitting in a drawer, and that a single backup disk is a bad bet.

A few copies that are not really separate:

• A second partition on the same drive. One person warns it plainly, and the people who raised it agree: if the drive dies, both partitions die with it. That is no backup at all.
• An external drive that is always plugged in. One person says a drive attached to the same computer can fail with it or be treated as the only copy. Some people warn an always-connected drive is exposed to the same viruses and ransomware as the computer, and the UK’s National Cyber Security Centre says the same: ransomware can move to attached drives automatically, so disconnect the drive when the backup is done.
• Everything in one place. One person warns never keep all of your data on a single machine or in a single location, and one person adds that a local disaster is more likely than a cloud company collapsing — which is why you want both.

Cloud storage, with its limits

Some people say that for most people, the mainstream cloud storage and backup services are enough, and one says a cloud backup counts as the off-site copy for personal use. It is automatic, it is away from your house, and one person points out that the data centres behind it have guarded buildings, spare copies and encryption.

The limits are real, and they are the reason the cloud should be one copy rather than the only one. Some people say cloud storage only lasts as long as your account and subscription do, and that services can close. One person warns an account can be banned by mistake — flagged for content it did not have — and the files go with it. Some people warn providers have had outages, one person says big providers have had breaches, and one says cloud data can be leaked by accident. On hacking, one person’s answer is that nothing is hack-proof, but a long password — sixteen characters or more — cuts the risk a lot. One more trap, from one person: some backup services delete your stored copy if your computer does not check in for a while, so if your only other copy then dies, you lose both. Read how long a service keeps files for a device that has gone quiet.

Some people say you can encrypt what you upload so that no one, not even the provider, can read it without your password — and they are clear that losing the password means losing the files, permanently. One person suggests a middle path: encrypt the sensitive things, like tax papers and private documents, and leave family photos unencrypted, so that a forgotten password cannot cost you the pictures. The free space the services give away is small: some people say it is enough for documents and schoolwork but not for video or years of photos, and some people say more space is cheap if you pay for it. One person adds that the cheapest deep-storage services can take many hours to give your files back, so they suit a last-resort copy, not the one you need today. And the cloud needs the internet: one person says that for people who work in remote places with no connection for long stretches, strict local backups are the only kind that work.

Whether the cloud or your own drives should be the main copy is argued over, and the deciders given come down to one trade: convenience and protection from fire and theft on one side, and privacy, no monthly fee and control of your own files on the other. One person says a drive is a one-time cost and keeps your data in your hands, where the cloud is a monthly bill and someone else’s building. Both are true; the 3-2-1 rule is how you stop having to choose.

Things that feel like a backup and are not

First, sync. Some people say a syncing folder is not a backup: a folder that syncs to the cloud copies your changes both ways, so if you delete a file on your computer, it can disappear from the cloud too. Some people recommend a syncing cloud folder as a backup, and both can be true, because some of those services keep older versions of your files for a while — two of those accounts mention the version history. What makes a copy a backup is that it can take you back to before the mistake. One person’s view is that the most common reason anyone restores a file is to get back the version from before it was overwritten by a broken one, and one person warns that if you back up a corrupted file over your last good copy, with no older versions kept, you have backed up the damage. The US government guidance makes the same warning about rolling backups: they can silently carry corruption or malware from your files into the backup. One person’s low-tech fix is to save important work under a new name with the date each time, so the old version is still there.

Second, RAID, which is not a backup either. RAID is a way of linking two or more drives inside one computer or storage box; the kind people mean when they call it a backup mirrors the drives, so if one dies the other carries on. Some people say the same thing about it: it protects you from one drive failing, and from nothing else — not from deleting a file by mistake, not from a virus, not from theft, not from fire. The mirror copies your mistake to both drives instantly. One person adds that if a home storage box is where your files actually live, rather than where your backups go, it needs its own copy somewhere else.

Third, a USB stick on its own is not enough. Some people say flash drives are too fragile to be your only backup, and one person warns that cheap sticks can report more space than they really have, so your files never fully arrive.

Three more things to include that are easy to forget. Your phone: one person says phones hold data too, and that a phone’s memory card is not protected by the phone’s lock, so encrypt it if you use one. The codes in your two-factor authenticator app: one person says losing the phone can lock you out of your accounts even if your photos are safe. And yourself: one person says backups do not protect against your own slip, like wiping the wrong drive or installing a new system over the backup. In one argument over antivirus software against careful habits, the point it ends on is that neither is enough without backups, and one person describes ransomware destroying the documents of people who had none.

Prove it opens

Some people say a backup is not a backup until you have restored something from it, because untested backups are often broken or incomplete. Individual people are specific about how they fail. Some people describe backups failing silently — corrupted, locked behind a lost password, or set up so wrongly that only a sliver of the data was being saved. One says backup routines break quietly over time — after a restart, for one — without any warning. One says you will forget to include a folder, and find out only after the disaster. One describes a workplace where the untested backups failed in the one crisis they were for, and another says companies find out their backups are broken only when they need them. The UK’s National Cyber Security Centre says the same: once you have made a backup, check that it really holds your important files.

So every now and then, restore a sample: open a few files from the backup, or restore them to a new folder rather than over your originals, and check they are whole. It is safe to test. Some people answer the fear directly — if the test fails, you have lost nothing, because you were copying the backup, not touching the original, and now you know to fix the backup. One person adds that it can be confusing in the moment: remember that you are restoring a copy, not overwriting the original. How to check a whole backup without restoring all of it, and which programs do it best, are questions this page does not cover.

Once the first copy exists, make it automatic if you can. Some people say automation is what makes backups last, because a job you have to remember is a job you will stop doing; your computer’s own built-in backup tool, or your phone’s cloud backup, is the place to start. One person warns that a scheduled backup only runs if the computer is switched on at that time. How often depends on what you make: some people say once a month is fine if you mostly store things you could recreate, and two say it is far too slow if you create your own work, because a month of it is a lot to lose. One person’s way to decide is to ask how much you could bear to lose, and set the schedule by that.

One person calls backups insurance: you pay in time hoping never to use it, and the cost of losing the files — the time, the money, the upset — is far bigger. Another says people resist backing up until they lose something, and that a shock or a pretend disaster is what convinces them; one says hearing someone else’s story of a dead drive is a reminder that works. If you are reading this before your loss rather than after, the folder you copy today is the one that will still be there.