The Backup That Looked Fine but Was Missing Files

A real job from summer 2026, anonymised. A local business, a backup that reported success, and an audit that found two quiet problems before they ever cost anyone a file.

The Problem

Nothing, on the surface. The business's managed backup was running and reporting. This audit was routine, part of actually checking backups rather than trusting green ticks. It found two faults that together meant the backup was worth much less than it appeared.

Diagnosis

First, the machine's OneDrive folder was set to Files On-Demand with content kept online-only. That means the files on disk were placeholders: entries that look like documents but hold no content until you open them and OneDrive downloads the real thing. A backup of a placeholder captures the placeholder, not the document. So a whole folder of business files was effectively absent from the backups while everything reported normally.

Second, the backup schedule itself: both daily runs were set for times when the machine was usually switched off, one in the small hours and one early morning. A backup that fires when the computer is off does not run at all.

The Fix

The OneDrive folder was switched to keep its content available on the device, so the actual files exist on disk and get captured. The two daily backup runs were moved into the working day, when the machine is on and the backup can genuinely execute.

The Outcome

The backups now contain the real files and run at times the machine is actually awake. No data had been lost, because the audit caught the problem before anything needed restoring, which is the entire point of auditing backups.

What This Illustrates

Sync and backup are different things, and this is the clearest real example we can offer. OneDrive was doing exactly what it was configured to do; Files On-Demand is a sensible feature for saving disk space. But a backup is only real if the content it is supposed to protect actually exists where the backup runs, at a time the backup can run. That is why our managed backup service includes checking what the backups actually contain, not just whether the job reported success.