How we actually test a backup (and why most hosts don't)

Every host claims to do backups. Almost nobody actually tests them. We’ve lost count of the times we’ve migrated a site in from somewhere else and the client has said “the backup didn’t work”. Of course it didn’t, nobody ever tried to restore it.

What a real restore test looks like

For every site on our infrastructure, we run the following cycle, monthly on smaller plans, weekly on Care+:

1. Pick the most recent backup.
2. Restore it into an isolated sandbox environment (separate VM, separate DNS).
3. Run an automated check-list:
   • Home page loads, HTTP 200.
   • 10 other random URLs load, HTTP 200.
   • The admin login page renders.
   • Database queries return a row count within 1% of production.
   • No missing plugins, no missing theme files.
   • WP-CLI reports no fatal PHP errors.
4. If any step fails, we page the on-call engineer. Real page, real engineer.
5. We log the result and throw the sandbox away.

That’s it. Nothing revolutionary. What’s revolutionary is that anyone does it at all.

What the test catches

In a year, this test has caught, across our fleet:

• A backup tool silently skipping files over 100 MB (caused by a bad config on one server)
• A database dump that had been corrupted for six weeks because of a MySQL timeout
• A site that backed up fine but restored to a different PHP version and 500’d
• A plugin folder that backed up but whose licence file didn’t, site restored but features were broken

None of these would have been visible without an actual restore. They would have been invisible until the customer needed the backup, at which point “invisible” becomes “career-ending”.

Why most hosts skip it

Testing restores is slow and expensive. Running a sandbox, scripting the check-list, maintaining it, none of that generates revenue. It’s much cheaper to just take the backups and hope nobody asks.

That works fine, statistically, until it doesn’t. And when it doesn’t, it’s the kind of doesn’t-work that takes down a whole business.

What to ask your current host

If you want to find out whether your current host is serious about backups, ask them three questions:

1. When did you last successfully restore my site from a backup?
2. Can you prove it?
3. If I ran a restore request right now, how long until my site was back on a fresh sandbox?

If the answers are “we haven’t, we can’t, and we don’t know”, you have a backup on paper, not a backup in practice.