Backing up your files so a lost device is not a disaster

If a laptop is stolen, a drive fails or a phone goes into water, what you get back depends on whether a copy of your files was made before it happened. A backup is a second copy of your files, kept somewhere other than the device they normally live on. Without one, the photos, documents and records on a failed device may be gone for good, and professional recovery is slow and can be expensive, with no guarantee of success.

A reliable backup does not need to be complicated. What matters most is a clear routine, a second storage location and a simple test from time to time.

The three copies rule

The rule usually described as 3-2-1 is a simple way to plan redundancy. Keep three copies of anything important, store them on two different kinds of storage, and keep one copy somewhere else. The original on your device counts as the first copy. An external drive at home can be the second, and a cloud backup stored in a different location can be the third.

Each part protects against a different kind of loss. Two kinds of storage guard against a failure that affects one type of device, such as a drive that wears out. The offsite copy guards against events that damage everything in one place, such as fire, flood, theft or a power surge that takes out every device on the same desk. You do not need a complicated arrangement to meet the rule. You need one extra copy that you actually keep up to date.

Choose automatic backups over manual ones

Manual backups depend on memory, and they are easy to forget. Use the backup feature built into your operating system, or a backup program you trust, and schedule it to run automatically. A cloud backup can run in the background whenever the computer is online. An external drive needs a routine of its own, because a scheduled run cannot write to a drive that is unplugged. Pick a fixed day each week or month, connect the drive before the scheduled time, let the run finish and then disconnect it.

Keep the external drive somewhere safe and disconnected when it is not in use. A drive that stays plugged in can be damaged by the same event that hits the computer, and ransomware can encrypt backup folders it can reach. Encrypt backups that hold sensitive documents if the tool supports it, and store the encryption password in a password manager rather than in the same folder as the backup.

Check that backups actually finish. A backup that stopped months ago gives little protection. Look at the date of the last successful backup regularly, and turn on a notification if the tool offers one.

Also decide how far back you need to go. Many backup tools keep several past versions of each file, which lets you recover an earlier draft or a photo that was overwritten. Check the retention setting, because a short history is of little use if the damage is discovered weeks later.

Why syncing is not the same as backing up

Cloud sync services keep files matched across your devices, which is convenient but not the same as a backup. If you delete a file on one device, the deletion can spread to every synced copy. If malware encrypts or damages a file, the damaged version may sync too. Some services keep deleted files or older versions for a limited time, but the period varies, so do not rely on it for files you care about.

A true backup keeps an earlier state you can return to. Use sync for access across devices and backup for protection. If you use a cloud drive, check whether it offers version history or a trash folder, and find out how long those are kept.

Cover your phone and its photos

Phones hold photos, messages and app data that are easy to lose and hard to recreate. Turn on the built-in cloud backup in the phone settings, and confirm that its latest run has completed and that there is enough storage for the data. Photos may be handled by a separate photo setting, so check that the photo library is included, not only the general device backup.

Also copy important files that live on the phone, such as scanned documents or saved receipts, to the same cloud service or to a computer. When you need to set up a replacement phone, the most recent backup is the one that matters, so check its date before you rely on it.

Test a restore before you need one

A backup is only useful if it can be restored. Once a month, restore one or two files from the backup to a temporary folder and open them to confirm they are complete. The check takes a few minutes, and it shows whether the backup works in practice, not just on paper.

Once or twice a year, go further. Restore a larger set of files drawn from several folders and from different years, and open each one to confirm it works. Include a few older photos, since problems sometimes affect only older copies.

Write down where each backup lives, which account it uses and how to sign in to it. In a real emergency, forgotten passwords and unclear instructions can slow recovery as much as missing files do. Keep that note with your recovery details, somewhere you can reach even if the device is gone.