Practical guide

How to verify that a backup can actually be restored

Restore a small set of files to confirm that the right files are present, readable, complete, and accessible with the account or key available during an incident.

Published September 13, 2026 · CDRinfo editorial desk

Choose a safe test set

Start with a folder you can recognise: a small photo album, a document project, or a set of files with a mix of sizes. Include one file created recently and one older file. Create a temporary destination called “restore-test” on another disk or in a separate folder. This keeps the test away from working data.

Write down what you expect before beginning: folder names, approximate file count, a few file sizes, and the most recent change date. These notes reveal when a backup has stopped including a location.

Restore the files

Backup interfaces often let you preview a file listing. Use the actual recovery procedure to restore the selected folder. If the backup uses encryption, confirm that the recovery key or password can be retrieved without relying on the same device being restored. If it is an online service, sign in normally and note any additional verification step.

After restoration, open representative files with their normal applications. Look at photographs at full resolution, play part of a video, and open documents. Compare the restored file count and dates with the notes you made. For especially important archives, compare checksums if your tools support them, then open the restored files.

Test an older version

A backup can copy today’s mistake. Pick a file that has changed recently and use the version history to retrieve an earlier revision. This is where retention matters. Recovering earlier revisions requires version history retained before an unwanted change.

Record what happened: the backup date used, destination, time taken, any account needed, and obstacles. A one-page recovery note helps another person restore the archive. Keep it with the household’s important records and update it after changing software, passwords, or storage providers.

Make failure visible early

Check the backup report occasionally and compare its sources with the locations you expect to protect. A disconnected drive, renamed folder, expired cloud payment, full destination, or changed permission can create a gap. Run a small monthly test and a larger annual folder restore to find gaps early.

For files that would be hard to replace, test the off-site copy because local and online backups have different failure points. Confirm that an independent copy is accessible.

Turn testing into a habit

Put a recurring reminder on the calendar. Pair the test with a familiar event such as the start of a month. A short, regular recovery check keeps the procedure familiar before an emergency.

Further reading: CISA ransomware guidance and Synology on reducing data-loss risk.