Time Machine to NAS "preparing" very slowly since 15.0

[Mightee]

Since updating to 15, my Time Machine backups have been running incredibly slowly. I have them directed to a Synology DS220+ every hour, and until now this has worked beautifully. Now, however, the "Preparing to back up..." stage takes anywhere from 60-90 minutes. Sometimes longer! Backups do eventually complete, which is nice, but the time it takes is a problem.

There is plenty of free space on the drive. I was hoping that the 15.1 update would fix the issue, but no luck. I have done everything I can think of, including re-enabling SMB on the NAS and deleting and reconnecting the TM path. It was also suggested to me that I turn off macOS' built-in firewall, but this was never on in the first place. (I did toggle it on and off again just to see what happened.)

Anyone else seeing this issue? Anybody find a fix?

 

[wiredup72]

Having the same issue with my QNap and I’m still looking for a resolution.

 

[Howard2k]

I just updated to 15.1. I wish I'd read this before, but luckily I have had no issues. I went from 14.7 to 15.1. MacBook Air M1. NAS backup working as previously - so far at least.

 

[wiredup72]

hmm, I'm on 14.6.1 and am about to update to 14.7.1 to see if that helps.

 

[Mightee]

Still an issue as of 15.3, so bumping. It's really driving me nuts.

 

[HobeSoundDarryl]

Have you tried removing the NAS like you don't want to backup to it anymore, maybe rebooting both it and Mac, and then adding it back again?

Also note that a generational update of macOS is going to write a LOT of new files to backup. Perhaps it just needs the time to deal with a significantly changed macOS?

Else, bugs are probable. My general rule of thumb is delay major updates until about the .5 or .6 update... roughly WWDC time. That used to be .2 or .3 but evolved as bug fixing seemed to have lost some focus at Apple for new-new-new. If you deduce bugs, perhaps take it OFF hourly backups and make it manual, then trigger manual backups before you go to bed at night. Let it run all night if necessary. It should be done by the morning and you won't experience the "slow" while you are asleep.

 

[Mightee]

Have you tried, removing the NAS like you don't want to backup to it anymore, maybe rebooting both it and Mac, and then adding it back again?

Also note that a generational update of macOS is going to write a LOT of new files to backup. Perhaps it just needs the time to deal with a significantly changed macOS?

I have removed and readded the NAS several times. Also increased its RAM and storage, made sure it’s up to date. (I might do this again though because why not, the .3 update just dropped.)

I thought about the generational issue, however I’d expect to eventually see improvement. This has steadily been a problem since 15.

 

[HobeSoundDarryl]

Probably bugs then. Here's hope for .3... but probably more like .5+.