What causes Time Machine to stall during backups?

I also migrated to a new M4 mini and all was well for a while but now I'm getting these TM errors (TM folder is on a Synology NAS server).

Try re indexing Spotlight. It fixes it for a few of us. For me wife 4 weeks, friends 3 weeks, myself had to reindex after two weeks.

Same on mine, so I suspect the folder only gets created temporarily, and that's when it's a problem. Adding the exclusion did fix it for me.

That is awesome! I've noted that and next time the issue occurs I'll carry this out and see if it fixes it!

It gets worse, this is not good news! Read this article. It has to be related.

It's still good for me. After reinitialising Spotlight it failed once (after about 11 days) and immediately I put in the Find My folder exclusion. Since that was done it has been completely solid with no failures at all.

The only other thing I've done was remove the backup to the NAS and now just backup to the hard drives. This was done as I found the NAS slowed down too much when backups ran at the same time on my Mac and my wife's.

She backs up to the NAS with the FindMy fix in place and again has not had any issues since I put it in place.

Very useful, I've altered mine to show as 'oldest' we'll see if it makes it easier.

I know none of my posts have broken the rules.

i tried to thank you, but the moderators thought my response was inappropriate. so . thank you for helping me be able to easily locate posts. we'll see if they let this one go.

This procedure worked fine.

I also tried another one with my NAS: I rebooted the Server and the Mac and requested another back-up. For a while the error message for failed backups persisted but when opening the TM Settings, I noticed that the NAS disk showed the time of a backup without a warning attached to it. After the second or third backup to the server, no failed backup messages showed up. It seems that it is all is well now.

You still have the Router firewall (most come with protection software, including a Firewall).

The TM back up will complete normally if you turn of the Mac OS firewall. Otherwise, you will continue to have issues.

I meant 15.1 which is out for doing the upgrade. So, I am going to wait and see if 15.2 has the fix. I am getting tired of these constant upgrades which change settings behind my back and clearly are not sufficiently tested. Having back up issues with the firewall is not a minor inconvenience. Bad Apple.

I just reported the defect you see with 15.1 and the one I saw with 15.0.1 with Apple Support. If you do, they will give you a case ID number and you can inquire with them when an update comes if it addresses the issue using the case ID number.

I am sorry to hear that the solution was to wipe out your hard drive and restore from a previous backup. So, I guess that you are now back in 15.0 which showed no issues with TM for me.

Yes so I ended up wiping the Mac and doing a restore from a backup. I got a conflict when restoring which I ignored.

So yep it didn’t restore properly so I’m doing it again this morning. Interesting when it downloads the OS to do the reinstall it uses Sonoma.

So while the OS part of the restore is taking place it’s our early doors for a coffee.

I will be going back to using Sequoia even if it has the problem again so I can feed back to Apple. I know from past experiences cases are help open for 30 days.

I reported it for both 15.0.1 and yours @dbrewood for 15.1. No point of putting my case ID number as it will be edited out in accordance to Apple’s terms and conditions for using the Community site. I guess that they do not want to accept that this is, in my opinion, major as it compromises two basic functions of the OS: TM backup and firewalls. I will not update to 15.X until they fix this issue. I have two other computers around and they will remain in Sonoma now that one cannot download 15 but just 15.1 which is busted.

[Edited by Moderator]

That isn’t what I posted. You need to get spotlight to reindex.

to do this add the main hard drive to the Spotlight ignore list, wait maybe 30 seconds and then remove it. This will start Spotlight reindexing on the drive.

You should be able then to check this by opening Finder and viewing most recents, you should see that list starting to populate.

Once that is there TM backups should now work with the Mac locked.

If your backups are screwed you may need to reinitiate them. Hopefully though you should be good after that is done.