Time Machine not working on macOS Tahoe 26.2

macOS Tahoe is absolutely the culprit. It messed up my almost three years of backups. After upgrade to Tahoe, TimeMachine started giving "disk full error" message even though it had consumed all the disk capacity.

Starting backups afresh on a freshly formatted disk did not help. Same error message. In frustration I ended up calling Apple Support. After about a month, of several screen sharing sessions, the following steps are showing promising signs of working again.

The fix at least for me involves starting backups afresh. So you will lose all your older Time Machine backup history.

The fix was to delete some backup related settings via the command line.

The commands to enter in a Terminal shell are:

sudo xattr -d com.apple.timemachine.private.structure.metadata /System/Volumes/Data
sudo xattr -d com.apple.backupd.ModelID /System/Volumes/Data
sudo xattr -d com.apple.backupd.HostUUID /System/Volumes/Data
sudo xattr -d com.apple.backupd.ComputerName /System/Volumes/Data
sudo xattr -d com.apple.backupd.BackupMachineAddress /System/Volumes/Data

After all this if

sudo xattr -l /System/Volumes/Data

returns

purgeable-drecs-fixed:

and nothing else, then in theory that is all you have to clean up before resuming Time Machine backup again.

Your macOS machine may not have all these values defined. So just ignore if the command throws an error or warning. I was too tired to challenge and optimize. I just ran the commands blindly.

After this, I reformatted the Time Machine backup disk and restarted the backup. It has been 24 hours and it has not thrown an error. So I decided to share what I had learned here early.

If I encounter failures again, I will post again. Try these steps and see if it works for you. Hope this helps you recover too. I am feeling somewhat relieved now knowing that I have a good backup again now.

I am thankful to Apple Support to help me recover.

I fixed the TimeMachine/Synology issue by changing the smb settings on the Synology. It seems Apple changed the negotiation with smb and Synology doesn't comply.

My settings are:

Max SMB protocol SMB3

Min SMB protocol SMB1

Encryption: disabled

Server signin: off

opportunistic locking: activate

SMB2 file leasing ON

SMB permanent handles ON

Worked like a charm, backups back on :-)

There have been reports of issues with TM backups to an NAS, though personally my Mac running 26.2 is backing up just fine to my NAS (a Synology DS223j).

One known issue is when the computer name or backup name contains a special character, the backups fail. For example, MacBackup would work but MacBacküp would not, because of the umlaut. Changing the name solves that issue.

When TM 'refuses to make backups' what actually happens? Does the backup start? Get stuck? Is there an error message?

I had the same issue with my Time Machine back up using Tahoe 26.2. Last night, 26.3 came through and when I installed it the issue was solved. My MacBook Pro backed up without any issues. Good new y'all!!!

Since I installed 26.3, I'm at my third daily TM Backup and all is fine, Thanks Apple!

ButtleTuttle wrote:

I fixed the TimeMachine/Synology issue by changing the smb settings on the Synology. It seems Apple changed the negotiation with smb and Synology doesn't comply.

My settings are:

Max SMB protocol SMB3

Min SMB protocol SMB1

Encryption: disabled

Server signin: off

opportunistic locking: activate

SMB2 file leasing ON

SMB permanent handles ON

Worked like a charm, backups back on :-)

Glad your backups are working again. Mine never stopped, 5 Macs in the house (two on Tahoe, three on Sequoia) backing up to a Synology DS223j, the two on Tahoe have been working normally all along and I have not touched the Synology settings that I initially set up per their kbase article.

I had the same problem. One piece of advice I found was to close down and reboot in safe mode then run the back up to my attached USB drive. I tried it and it worked. Better still, I have had no problems with time machine since.

Installes Tahoe 26.3 yesterday, Time Machine fixed for me!

Latest update for my part: I found a solution!

As I already have a Carbon Copy Cloner license, which I've been using as my client for keeping a bootable copy for my system as well, I turned to their ordinary day-to-day back up solution, and it works perfectly. Of course, it works differently than TM's flipping-through-previous-versions interface, but it does, what it's supposed to - which is a lot more than can be said of Time Machine.

So in short, my solution to Apple's self inflicted Tahoe Time Machine Mess is:

Bye, bye TM, hello CCC!

Because, as they say: A back up is always better than a slip-up!

I to have the problem :-( so i choose to get a CCC license and a new SSD Samsung T7 and start from the beginning with Carbon Copy Cloner and it works like a charm :-)

So, like so many others, upgrading to Tahoe totally ruined the ability to make TM back ups which have functioned without issues for as long as I can remember, across a number of different Macs and drives.

In my case the back up of my 2020 14" Macbook Pro M1 is set to take place on a NAS or home server - a late 2012 MacMini running Catalina with an attached JBOD raid consisting of three 1TB discs (one internal and two connected via usb).

My MBP has 1TB of storage and around half of that is free, so 500GB should fit into 3TB nicely and has done so up to this point. However, I soon realised I could not continue on the old back ups made prior to Tahoe, but had to erase the NAS and start over. At first the attempted backups would fail as the first back up would never finish. It would also not just add to what was already backed up but keep adding to the data and eventually filling up the discs. Also, I would not see a "sparsebundle" file created but instead a folder with my name!?

Numerous attempts to delete the recipient discs and recreate the RAID using APFS protocol, but it still followed the above pattern.

After upgrading to Tahoe 26.3.1 I read the suggestion on here from rahulj123 and followed that. At first it seemed like it finally worked. An actual sparsebundle was created and most of the data was transferred, but again it never finished, and whenever I try to start TM back up again to finish the initial back up, the connection with the server is lost.

To the best of my knowledge, it's not a network issue, as everything else works fine, including screen sharing with the MacMini (which has worked throughout).

So there has to still be something with the OS that renders the TM feature unusable, and it's driving me to the brink of discarding it altogether.

This, for a company like Apple that prides itself in having systems that are both plug-and-play and work by and large without hassle, is a major setback.

I had the same problem. Went with Samsung T7 1 TB SSD and Carbon copy cloner :-) works flawlessly- Time Machine dead and buried!!

Using Tahoe 26.2 time machine will not back up. sends message “/Users/bobferguson/Library/HTTPStorages/com.microsoft.EdgeUpdater/httpstorages.sqlite-wal” could not be backed up. File HTTPStorage..... does not exist on computer.