Timemachine Back-up in MacOS 26 (Tahoe) does not work on Synology DS920+ NAS

Have you tried the suggestions posted at the top of this thread by karel250? I have also seen posts somewhere, don't recall where, that non-English keyboard with special characters cause problems. If this applies to you then you might want to check for that.

I too have been having problems backing up over the wire to my DS216+II in the past few weeks (Mac Mini M4 running 26.2). My TM logfile was filled with errors and although I could hear my hard drives working during a backup and see the restore selections, the errors bothered me enough that I purchased a well known 3rd party backup solution.

Today I spent a lot of time deleting my TM backups and setting it all up again as new. I had to use Synology Filer to delete all the files in my TM directory on the NAS, I did not delete the TM folder on the NAS. Snapshots are saved locally on my Mac, I had to use Disk Utility to delete all those snapshots and remove the mounted partition to NAS. I deleted TM setup in System Settings and then Shutdown and did a 'Recovery Startup' (sorry, I don't know the proper name) and started up without doing a recovery option (not a normal startup after shutdown). I did this to wipe the caches and whatever residual memory of TM's prior install. No idea if that was necessary.

I set up TM again, making sure I followed the suggestions of karel250 and the Synology Knowledge base article on TM. I use SMB3 and NOT afp. I reused same NAS directory, UID, and pw as I had in the past. It took nearly 3 hours over ethernet to complete a new backup and appears to be in good order but only after the next few days/weeks will I know for sure. Unfortunately, I no longer trust this method of backup and having purchased the 3rd party solution it backs up the /data folder in about 3 minutes via thunderbolt vs almost 3 hours over ethernet. I'll keep using TM scheduled backups but I'm going to be relying on my new backup solution.

Good luck, hope this helps

TimeMachine was working under Tahoe 26.1. Then I "upgraded" to 26.2, and the problem started again.

Mac Studio 2023, Synology DS923+

I can't even delete and recreate a new backup now. "The selected network backup disk does not support the required capabilities. Please be sure Time Machine capabilities are enabled on the server for this volume or choose a different network backup volume."

I did not change anything about the Synology disk before or after going to Tahoe 26.2.

Thanks for this tip. I am using English keyboard, most posters here seem to be using foreign keyboards. Backups had been makeing lots of disk acivity and after I changed he nsmb.conf to sighing = yes. it took some time for the restore timeline to appear but it finally did. I have not verified a restored file yet but all seems to be wording well.

Thanks!!

Hi, Today, after upgrading to Tahoe 26.2, I have the same problem with diacritics other than English. Renaming using the Disk utility helped.

Thx

What I did was:

1. Try to backup to Synology (I have a Synology Disk Station DS124)
2. This will fail but the disk image has been created
3. Mount this image using Finder -> Connect to server...
4. When mounted, open Disk Utility
5. Select the mounted image (see picture above)
6. Just change the letter or letters not suitable for whatever encoding Apple is using. In my case the 'ä' in "Säkerhetskopior"
7. Re-start backup, if it fails try unmounting the image
8. Re-start backup again

It takes several hours for the first complete backup but at least I got my USB connected external drive back, to use for other things than TM backups.

Finally figured this out. It took me a while to realize where to change:

The name of the backup disk will have its name set in the language used in your OS. In Sweden it will be "Säkerhetskopior av [your computer name]". And when I changed that ä to an a it worked although not immediately. I started the Time Machine backup but told me the backup disk was already in use so I unmounted the disk and started the backup again and voila!

I hope it helps.

I'm just worried that this workaround will break when Apple fixes this?

Sharing is caring.. There is a bug in Samba versions 4.21-4.22 that conflicts with Tahoe for Time Machine. It is the current version at the time of this writing. It should be fixed in 4.23, or if you can downgrade to 4.20 it was successful for me.

https://bugzilla.samba.org/show_bug.cgi?id=15926

I have the same problem as everyone else. Changing all characters in folder and file names from Swedish to English didn't make any difference. I've also tried the proposed solution from karel250 but that didn't make any difference. A solution that worked was changing the Mac's preferred language from Swedish to English. A one time solution that won't work in the long run. I suppose that developers in California only test with their native language

Hi all,

I have been facing the same trouble during the backup - my disc was disconnected. I opened the disk utility as another user in this conversation and I found the backup image bundle name "Zálohy svazku ..." has in it's name the letter "á", so I renamed it to "Zalohy svazku ..." and now the time machine backup works.

Hi all,

I have been facing the same trouble during the backup - my disc was disconnected. I opened the disk utility as another user in this conversation and I found the backup image bundle name "Zálohy svazku ..." has in it's name the letter "á", so I renamed it to "Zalohy svazku ..." and now the time machine backup works.

THANK YOU!! The real solution for me was to RENAME the APFS Drive! Thank you SuperMek_original!

I was struggling in the last two weeks to make it work. I tried everything including the solution marked as the famous. That DOES NOT worked for me! Only the renaming worked because my APFS disk name is had also contained special characters like () and áéöő. So I renamed it to TimeMachineHP with the disk manager and immediately started to work. Thank you!

I have the same problem using a qnap for my Time Machine Backup. Changing SMB Server Settings and /etc/nsmb.conf did not fix the problem.

Works like a charm for me. Thanks so much.

Thank you. Backups finally working again. Problem was Záloha (translated Backup) in image name / description or whatever it is.

Did this. Helped against my old Synology DS-414 (had a backup). The new Synology DS-923+ wasn't happy though. Found out I could change my computer name though and this looses all my Swedish characters. Time Machine running now and I'm waiting for success!

Check your netbios and wins name!