After upgrade or new install of Big Sur, TM backup stoped working to Synology NAS using AFP or SMB3 protocol. TM to external USB works fire and other 4 mac's with Catalina can create TM backups to the same NAS without a problem.
MacBook Pro 13″, macOS 11.0
Here's what I did overall to get it working and it is now working on all my Big Sur implementations (4):
But before doing any of that take a look at the Connections log on your DSM (DSM>Main Menu>Log Center, and select Connections from the drop down menu. Check if when a Time Machine backup initiates whether you have more than one user attempting the connection. For example, I noted that when my backups failed I would have two (2) users that had privileges to that shared folder attempt to connect nearly simultaneously from the same Mac even though I had only supplied one user credentials when selecting the share in Time Machine setup. I have no explanation or even speculation as to why that was happening.
I suspect there is a bug lurking in Big Sur regarding Apple's choice of APFS Time Machine backups that causes it to not play well with NAS devices, or in particular Synology NAS devices. It won't surprise me in the least if this is addressed in an 11.1 release. Everyone knows the 11.0.1 release was rushed to coincide with the M1 Macs show, and may not still be ready for primetime. I have a Mac I use as an Apple Music/TV/Plex server that relies on a 24tb SoftRAID RAID5 array that I cannot transition to Big Sur until SoftRAID is able to release an update (they claim their updated driver is built into the Big Sur release, but users are reporting issues and the client is beta and will be for some time). I'm just not going to risk that machine to some fatal bug that totally borks a 24tb array.
I have to update my own post: out of nowhere and with no changes to the NAS settings or the fresh install of Big Sur (I've never installed Sophos, but the machine does have a corp. copy of anyconnect installed that's complaining mightily about not being enabled...I don't think it relates to this), overnight a fresh "first backup" of the Big Sur install in question completed over the network to my Synology NAS.
...But here's the weird part: I was expecting that new backup to be "xxx.backupbundle", but it's still "xxx.sparsebundle". I'm not sure what that means as I was under the impression that we would stop seeing .sparsebundle backups from here on out and .backupbundle would be the thing going forward from Big Sur. To make it more confusing, I have another machine that came with Catalina installed and was system-migrated from it's previous machine and it's backups on the NAS are "xxx.backupbundle" format, and it's PREVIOUS machine (the source of the data for the system migration to the new machine) that started it's life here backing up long about early 2019, are also "xxx.backupbundle"?
I would think that the format of the backup archive, being sparsebundle or backupbundle, isn't determinative of this problem.
Unfortunately I have no solution for you; just a commentary on what I and others have experienced in the transitions from Mojave-Catalina-Big Sur regarding Time Machine .sparsebundle and .backupbundle backup files.
Up to Mojave, TM backups were saved as <xxx.sparsebundle>. With the advent of Catalina, TM backups were saved as <xxx.backupbundle>. There followed many complaints that TM backups saved prior to Catalina as .sparsebundle files were not recoverable in Catalina. Some folks claimed that changing the file name extension of pre-Catalina TM backups from .sparsebundle to .backupbundle allowed recovery of pre-Catalina, TM .sparsebundle backups, in Catalina. You may try this approach but this did not work in my case. Fortunately I have a reserve 2015 MBP (Mojave), from which I can recover pre-Catalina TM .sparsebundle files from my Synology NAS.
Now, by Big Sur decree, the TM file name extension reverts to .sparsebundle. One might reasonably expect that by so doing access to pre-Catalina TM .sparsebundle backup files would be possible. I have yet to find a way and I don't know why it does not work. Maybe it's the T2 chip (currently 2019 MBP-Big Sur 11.1) or recent Catalina and Big Sur modifications to APFS and SIP. At their convenience, not ours, Apple may provide a solution.
Your situation is fairly common and another example of how from time to time Apple, apparently without a second thought, cuckolds its clients.
Regards,
Jan.
My NAS is Allison on this version. I updated my Mac Mini (final Intel version) yesterday. I also checked too ensure the NAS was only using SMB 2/3 (although it unhelpfully describes the connection as CIFS). I use the same account for time machine as I do to access the NAS. Backup ran smoothly and continues to do so. Not sure if this was due to the .1 release of MACOS or release 3 from Synology, but all appears to be well!
We figured this out that antivirus/malware software could be a problem. In the meantime Cisco released new update for their SW and now TM is working.
If you are not bound to Sophos try to install BitDefender. Some of the guys up here reported that with BitDefender TM is working fine from Day One.
If you are bound to Sophos then report an issue at vendor and hopefully they will release new Sophos version somewhere in future.
I was able to get it working by following the steps in this article: https://www.synology.com/en-us/knowledgebase/DSM/tutorial/Backup/What_should_I_do_to_fix_the_problem_when_connecting_to_Synology_NAS_using_Time_Machine
I have one user with access to the shared Time Machine Folder on the NAS. I have only SMB enabled and left the advanced settings for SMB as default.
TM is backing up now, keeping my fingers crossed that this is not a recurring issue.
Thank you OR8cle! Finally that's the solution. I saw the TimeMachine account logging into DSM two times in a short time when the backup was started, or when the TimeMachine was searching for a backup-disk. I have no antivirus/malware software installed, so that could not be the problem. Apparently the macOS keychain was corrupted in some way.
Nit is not related to Synology. It is a problem of 3rd party malware software installed on Big Sur and not being updated for Big Sur. I have noticed that some of the vendors updated their SW and that solved the problem. So if you have any malware SW on Big Sur remove it and try to do a TM backup again. Report back.
i was able to solve the problem after update Cisco AMP. With Big Sur and Cisco AMP Version 1.14.0 the TM backup doesn't work. After upgrading to Cisco AMP Version 1.14.1 every works fine.
another MBP with Catalina has no Problem with TM and Cisco AMP Version 1.14.0. The Backup is terminated on the same Synology.
Thanks everyone for solve the problem
That is all well and good, but I think the origin of this story (at least for me) was the use of Sophos Home Anti-virus/malware protection with Big Sur, which was causing failure of all NAS-based Time Machine backups. Sophos has acknowledged the problem (see https://support.home.sophos.com/hc/en-us/articles/360051251412-Support-for-macOS-11-Big-Sur-#h_01ESKVJQVKHGVSQFA7E820FX45) and believe a fix will be available in March 2021. In the interim, their so-called "fix" is to perform NAS backups in Safe Mode (not - I just uninstalled Sophos from all my Big Sur machines for the time being, and if this persists . . . well, then Sophos will be no more).
Another poster sent me this link earlier:
https://discussions.apple.com/docs/DOC-8841
Especially with Big Sur that has built-in anti-virus, there's no need for third party software at all.
Phil,
I have found this on Synology community site:https://community.synology.com/enu/forum/1/post/138441
Some of them have the same problem as we have.
Regards,
Alex
I have tried on two different Synology NASes and the same result. I have macbook pro 13 early 2015.
Regards,
Alex
Yes that is the way and it doesn't work. It starts the backup, but it is very slow and after some time (5 min) stopes the backup without any real error.
Regards,
Alex
I have checked this and I already have this configured as you suggested. It didn't help in my case.
I don't use Sophos. I have tried without spotlight and it's the same result.
I don't know what to do to troubleshoot on both sides. Any ideas?
TimeMachine Big Sur to Synology NAS
