Verification failed
What the check after each backup does, what a failure means for the set, and the question about the destination drive it is really asking.
On this page
After writing a set, the run reads every stored file back and compares it with the set's manifest before it counts as complete. Verify files after each run is on by default, in every edition, on every kind of destination. While it runs, the phase says Verifying and the progress line counts Verified 1,200 of 2,943 files. The report then says OK, 2,943 files checked.
When it fails#
The report's Verify line reads Failed. The run finishes amber, Completed with skipped files, and its Errors tab lists each file that did not match, with the reason The stored copy failed verification (E-SET-002). The notification says the backup finished with skipped files.
The rest of the set is fine. Do not rely on the listed files from this set.
What to do#
- Run the job again: Retry on the report's result banner, or Run now on the job. If the drive was only disturbed during the check (a USB cable, a NAS hiccup), the new set verifies clean. The failed set is not checked again; the new one replaces it as the latest point.
- Restore from an earlier point if you need the listed files now. Every earlier set is unaffected.
The question it is asking#
A file written and then read back different means the destination changed it: a failing USB drive, a NAS disk on its way out, a bad cable, a card reader. One failure can be noise; two on the same drive is a message. Run the drive maker's check, and think about a second destination for the job.
Cloud destinations#
Verification runs on S3 buckets too: it downloads every object the run stored and checks it. Providers that charge for reads or downloads bill that. For a large cloud job where that matters, untick Verify files after each run on the job's Settings step, and restore a file now and then to check.
When you restore#
Every file is checked again as it is restored. A file that does not match is not written; the restore report lists it on its Skipped tab with Did not match its checksum: a wrong password or a damaged backup. Try the same file from another point in time.