Sequoia Time Machine Synology NAS keeps disconnecting

Don't know if this is what did it since I've tried several different things, but I went to Network>Firewall>Options and added the Time Machine app to the list of allowed connections. I've had one successful backup since, but it's such an easy thing to try, I thought I'd post it.

Similar issue, using different NAS

MacBook Pro 2019, macOS Sequoia 15.0.1 + WD EX2 manually updated to samba 4.18.8 including required extensions support for Apple and TimeMachine.

Worked ok using ethernet and as soon I started using Wifi I got continuous disconnection errors. Disabling Firewall helped succeeding after couple of retries, now testing enabling it back including it expectedly within allowed Firewall apps. I also use Little Snitch Version 5.8 (6402), I have been using it for years without any problems.

Im having a similar issue. We use a Synology Nas to edit footage from. Its been fine for near on 2 years. I updated (mistake) 2 weeks ago and then all of a sudden monday monring the server is disconnecting whenever it needs to do something ie: Exporting a video, reading the timeline, importing photos. It doesnt seem to matter about the file size. It just disconnects. Any ideas here? its only an issue with the NAS. Other drives like the Black Magic Cloud unit is fine. Also transfer speeds have slow right down

Hi BlueJayNE,

I don't think it is related to MAC address selected, in my case I used fixed one and it works or fails just depending on having firewall enabled or disabled.

After reading your comment I have given a chance disabling the WIFI MAC address privacy and results remain the same, that is Time Machine Backup works or fails depending on the Firewall status.

Maybe others can try and share their experiences.

Hi melv2,

In my case I tried providing explicitly full disk access to Time Machine and result is the same, it only works when firewall is disabled.

Looking forward to test with MacOS 15.1 version once released, as there is a comment with the RC version it works.

Hi everybody.

Glad to hear other people are finding the firewall solution works.

Sadly, not the case here - my iMac Pro is still failing to complete backups with Time Machine reporting the networked Synology is disconnecting (it isn't). I've never had firewall turned on and it is most definitely turned off.

Apple never got back to me as they promised, so I guess I will need to start the whole task of raising the issue and having it escalated again.

Obviously, I will report back if there are any developments.

I'm on MacBook Pro M1 with Mac OS X 15.0.1. With firewall turned on, all my Time Machine backup would fail. To the Synology NAS or to a USB drive. Tried adding Full Disk Access to the Time Machine app to Privacy & Security and it didn't help. Just had to turn it off for both to work…

Same here, as soon I have updated to 15.1 next scheduled backup worked like a charm. I will post in case future ones fail.

My setup is MacBook Pro 16" 2019 (intel) + WD EX2 NAS with samba manually updated to versions supporting TimeMachine over Samba.

Upgrading from 15.0.1 to 15.1 today fixed it. Could create a new initial backup of about 250 GB within 2 hours. It failed 2 times during that, but always continued where it stopped and after completion a "verify backup" succeeded. Also a good new timemachine feature is the limitation to certain size when creating the initial backup in the advanced options. Previously that required quota settings on the shared folder which is now not needed anymore.

I confirm my problem is fixed after upgrading to Sequoia 15.1.

After 15.1, I ran a backup with firewall off - worked fine, as it had since I turned off firewall with 15.01

Turned firewall back on, ran new backup - worked fine.

Now resolved.

Glad to hear some people are getting backups after upgrading to 15.1. My iMac Probackups to a Synology NAS are still falling over with the disconnection error when the machine is unattended and has gone to sleep during a backup.

I have sent a whole lot of log data to Apple engineers at their request and am waiting for a response.

Sigh.

Well that's odd - it's started working of its own accord.

Long-time readers might remember that my iMac Pro continued to report network disconnections after upgrading to 15.1. I forgot to disconnect the drive overnight, so the Mac tried to do another backup - which worked. And it's been quietly backing up every hour since.

So I think the 15.1 update does resolve this issue. Why I got an error? No idea, but I'll be glad to never see this again.

Appears fixed in Sequoia 15.1 (definitely broken in 15.0.1). I am now able to turn my mac's firewall back on. There was also an update to Synology DSM 7.2.2-72806 I installed at about the same time. So between the two updates, it is now fixed.

This worked for me. My synology DS218+ hadn't updated past 7.1.1 because of an old package I had installed that was no longer supported in 7.2.2. Updated to the new version manually, and it started backing up immediately.