An untested backup is not a backup, it's a wish.
this post was submitted on 18 Apr 2026
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Also known as Schrödinger's Backup.
Schrödinger did not have a backup cat.
Well, he did and he didn't...
Restored my backup and have all and none of the files, sir. Don't look at it until we fsck.
But he had quantum entanglement
How do you guys test your backups?
I have restored my proxmox setup from backup and it worked, but that is not something I do on regular basis.
I have from time to time done spot checks that certain files are working.
Most of the time I rely on the verification done by proxmox backup server..
How do you guys test your backups?
The image backups I do of my server are tested in a VM
PBS verification is only a checksum of file integrity. If somehow the backup was zero-length, or was otherwise corrupt, the verification would succeed but the backup would be useless. How often you do file or full restores is up to you, but required for actual verification.
That's a gimmie. I test server image backups in a VM. So far, I've never had to resort of a backup, but I don't want to find out that my image is worthless if I ever had the need.
Narrator: The fire detector in fact did not work.
There's more than one kind of backup in life, check them all.
That’s one I’d have the facility owner hire someone to test.
3, 2, 1.... Test the backup!
... Is that the rule, right?
From now on!
Two backups is one and one is none.
Two untested backups are worse than one tested backup though.
I run Borg backup, and I did a successful live test yesterday. Deleted the wrong file and hade to restore it.
this drove me nuts at workplaces. we have to test the backups after backup. so many did not want to waste the resources. if it worked fine once it will always work fine to them.
Sounds like there's room for a tool that checks backups
or ai that evaluates. For me the backup works if the whole system actually works. Its more commonly known as disaster recovery.
Somebody tell that to tindie.com !
Who's that?
rule of thumb. any backup you don't regularly test isn't a backup.