Oct 18, 2026, 12:56 AM@maddy @NanoRaptor beginner question: I make backups and make sure the files are readable, but the only way I can figure to test them as full backups is to try to restore my whole computer from empty, which, if it doesn't work, is not good. Has happened (not as a test but in a real failure case, I was unable to reinstall the OS). what logical step am I missing?
@iris @maddy @NanoRaptor
If you want to be really confident, you can restore your backup into a qemu or whatever VM. Simulate a total disaster recovery, but without the disaster.
Oct 18, 2026, 1:02 AM@silvermoon82@wandering.shop @iris@neuromatch.social @NanoRaptor@bitbang.social Also can't hurt to have backups using different tools (like Veeam Agent free in addition to Clonezilla, or whatever), or an 'if all else fails' backup with all your important files.
Oct 18, 2026, 1:04 AM@maddy @silvermoon82 @NanoRaptor both good tips, thanks!
@iris
> the only way I can figure to test them as full backups is to try to restore my whole computer from empty […] what logical step am I missing?
To test something safely typically implies redundancy: You have a spare/sacrificial whatever, that *is not used for anything else*, wipe it clean, and test on that. If the test demonstrates failure, you haven't lost the valuable one. In either case, wipe it clean for use testing next time.
In the case of testing backups, you bear the expense (money, time, storage, whatever) of a replica computer, as close to the real thing as you can make it. That's what you restore backup onto, and verify that the restore has actually brought back everything you backed up; then wipe it for the next time you need to test.
Look into “virtual machine” if you want to go down the rabbit hole.
Oct 18, 2026, 12:04 PM@bignose @NanoRaptor @maddy yeah, I don't think a spare entire computer is a reasonable ask for most people. shouldn't be what we expect when we say "test your backups".
I've worked with VMs before and that part I can try.
@iris @maddy @NanoRaptor This isn't an actionable answer, but ideally a backup system should have a way to output a list of pathnames and hashes extracted from the backup, so that you can compare against the live system to prove everything was there in the backup without needing temporary space to actually restore it all.
@dalias @iris @maddy @NanoRaptor It should. But that only proves that it can restore the files that are actually in it. Maybe a misconfigured exception rule was catching files it shouldn't. Or you have dependencies: like your password safe with the backup password is inside the backup. There are many things that can go wrong. Simulating a DR situation, actually restoring and testing whether you can continue working is a good practice.