After many trials and errors I got the restore finally working:
- rename the extension from
.sparsebundleto.backupbundle - connect Time Machine to the NAS => it'll state no backups
- do a backup => latest backup shown as of today
- reduce the quota of the Time Machine user to have 500G free space left
- do another Time Machine backup => this forces Time Machine to clean up the backup and get rid of older snapshots
- enter Time Machine => older backups are now shown!
- restore
Moral of the story: Do not rely on Time Machine, it's too buggy! I am installing an rsyc cron to sync all files below my home directory to the NAS. I still use Time Machine, which is useful to restore single files.
I am posting this here in case anyone has the same issue.
Answer from Peter Thoeny on Stack ExchangeTime Machine: "No macOS system backups we… - Apple Community
Have an Intel MacBook Pro. I used Time Machine to back it up
No OS X system backups were found - Apple Community
No macOS system backups were found on Time Machine
Is the Time Machine backup safe?
Why does Time Machine backup keep failing?
Does Apple Time Machine save everything?
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So I installed the Big Sur public beta and just didn't like it so I decided to downgrade back to Catalina. I made a new Time Machine backup and successfully downgraded to Catalina, but now for some reason it doesn't recognize the files on the Time Machine backup. It recognizes the drive as a Time Machine backup, tells me that it contains several gigabytes worth of files, but it doesn't seem to be able to restore them or even show them. It isn't recognized in Migration Assistant, and when I tried to restore in Recovery, it gets recognized as a Time Machine backup, but it tells me that "No MacOS system backups were found" when I try to restore it. Any help is appreciated.
Edit: So it was all a matter of compatibility. I went back to Big Sur and everything figured itself out. Still kinda looking for a way to downgrade if anyone wants to point me in that direction, but otherwise my initial problem has been solved.
I'm having some trouble here trying to figure out a problem with my Time Machine backups.
I wanted to test my Time Machine backups to make sure that if there was a problem I'd be able to restore from it. I boot up to no OS and select "Restore from Time Machine Backup". I point this to my NAS and select the correct backup. However, when I find the correct backup it always says, "No Time Machine Backups Found".
I thought maybe this was a problem with TM and the NAS but all of my other Macs have no problem finding the Time Machine backup on the NAS.
I've also deleted the backup and redid a full backup and I'm still having this problem.
This is a 2007 iMac running 10.8.5.
Any ideas?
Thanks for the help
It could be that the backup is missing system files. I've had this problem before.
First I have to ask: When you backed it up, did you back it up as a NAS or did you connect the drive directly to your computer and back up, then put the drive back on the network? If you did the latter, that's the problem: a network backup wraps the whole thing in a sparse bundle while a local backup (a drive connected directly) just puts it straight onto the drive. When you connect to it over a network, it expects it as a sparse bundle.
If that's not it, make sure your NAS has up to date firmware. After Lion (I think), OS X stopped using older forms of AFP to make network connections because they were inherently less secure than the newer methods. Some NAS still use the old standards and thus things don't connect or don't connect properly.
You can check out this article to see how to enable older styles, but most NAS have updates to take care of that.
Those are some quick things to consider. Beyond that, you'll have to determine if the problem is the NAS, then network, or the computer through experimentation. Try backing it up to a normal drive and see if it's recognized then. Try seeing if your computer can see another computer's backup on the NAS. Stuff like that. Test with different arrangements of things to get more details. Full blown troubleshooting.