Backups That Actually Restore

The failure is rarely an absence of backup. It is a backup that reported success, or covered the wrong things, or was a copy that faithfully replicated a deletion.

Sync is not backup

The most common and most damaging misunderstanding.

A sync service mirrors state. Delete a file locally and it is deleted everywhere. Encrypt everything with ransomware and the encrypted versions sync. Corrupt a document and the corruption propagates.

Version history helps and is limited. Most services retain versions for thirty days, per file, and restoring hundreds of files individually is impractical.

A backup is a separate copy that does not follow your changes. That independence is the whole point.

Sync is genuinely useful. It is not a backup, and treating it as one is why people with cloud storage still lose data.

What a backup needs to be

Automatic. Manual backups stop happening within weeks.

Versioned. You need the file as it was last Tuesday, not just as it is now.

Separate. A drive permanently attached to the machine is exposed to the same theft, surge, and malware.

Verified. A backup nobody has restored from is a hypothesis.

Off-site, for anything that matters. Fire and theft take the computer and the drive next to it together.

The arrangement that works for most people

One: the platform's built-in backup to an external drive. Time Machine on macOS, File History or a system image on Windows. Automatic, versioned, and it handles the whole machine.

Two: an off-site copy. A backup service, or a second drive rotated to another location. Cloud storage sync does not count.

Three: know what is not covered. Both platform tools have exclusions, and application data in unusual locations is frequently missed.

Two copies plus the original, one of them elsewhere. That is the whole strategy and it is enough.

Test the restore

This is the step that separates a backup from a belief.

Restore a single file from a month ago. Confirm it opens and is the correct version.

Restore a folder to a different location and check the contents.

Once, do a full restore test if you can — to a spare drive, or a virtual machine.

Do this twice a year. Backups fail silently: the drive fills, the destination disconnects, permissions change after an update, the schedule stops running. All of these report success or nothing at all.

What backups routinely miss

Anything on a phone that is not synced.

Application data in non-standard locations, including some mail clients and development environments.

Databases in use, which back up inconsistently unless stopped or handled properly.

Files on external drives that were not attached at backup time.

Cloud-only content — documents that live in an online service and exist nowhere on your machine. If the account is lost, so are they. Export periodically.

Authenticator codes, deliberately excluded by design.

Encryption keys and recovery codes, which are exactly what you need after a disaster.

The ransomware consideration

Malware that encrypts files also targets connected backups.

A permanently attached drive is likely to be encrypted with everything else.

Versioned cloud backup with retention is the practical defence, because previous versions remain.

A rotated offline drive is stronger, since it is disconnected most of the time.

Immutable or write-once retention, offered by some services, is stronger still.

If a backup is always connected and always writable, treat it as convenience rather than protection.

Phones

Phones hold the photos people would most miss and get the least attention.

Platform backup covers most of it, and specifically excludes authenticator codes and some app data.

Cloud photo services are sync, not backup. Deleting a photo deletes it everywhere after the trash period.

Export the photo library periodically to a computer or drive. This is the copy that survives losing the account.

A realistic starting point

If you have nothing: buy an external drive, turn on the built-in backup tool, and let it run. That single step covers most scenarios.

Then add an off-site copy for the things that are irreplaceable — photos, documents, records. Those are usually a small fraction of the total and can go somewhere separate cheaply.

Then restore one file, to confirm the whole thing is real.