Time Machine backups taking long, after macOS Sonoma update on my MacBook.

I have the same problem. Both on a Mini M1 and a MacBook 14 Pro M1 Pro.

Backups worked perfectly on Ventura BEFORE upgrade and instal of Sonoma 14.1.

Both make Time Machine backups each hour. To local external disk, and to a networked share.

Backups are 2TB (max size) for the M1 (HDD and network) and 4TB (max size) for the Macbook 14 Pro (SSD and network). In total a maximum of 12TB. All are encrypted.

None of the backup targets are full., but they contain recent history (document versions, code versions etc), that I do not want to loose.

In energy saving, I have specifically set "Don't go to sleep, when screen is closed", and 5 seconds after screen closes, password or fingerprint is required. The M1 has an Apple keyboard with fingerprint reader. Works.

There have NEVER been problems with this setup BEFORE Sonoma 14.1

AFTER, I periodically get the error message: "The file “BackupDisk” couldn’t be opened because you don’t have permission to view it." I have some choice words for that statement.

I can reproduce the following:

If I work on the machines: No problems. TimeMachine will do, what it has to do. So accessing the local drives or remote networked backups is no problem. Credentials work. Data is correct. Time Machine can access ALL four backup targets without problem. I have permission. Unrestricted and any time, the computer screen does not go to sleep.

Whether the backup takes minutes or hours. NO DIFFERENCE.

If I decide, that I do NOT want to sit by the computer for hours on end, just to make TimeMachine Backups possible, and leave the machine to continue on it's own, the screen will of course go to sleep (no pause screen). The display (internal or external) turns off after the specified timeout of 30 minutes (on external power). Works.

I have NOT tested in battery mode, YET, but assume that if you use shorter display timeout in battery mode, you'll experience the problem far, far more often.

The problem seems to exclusively being triggered, byt the display turning off (probably with a five second grace period). When I activate the keyboard, and log in (fingerprint), the TimeMachine backup has stopped, with a red exclamation mark, and the above error.

There are NO credential problems, before the screen goes to sleep (which is standard) and requires a password for login (which is standard basic security procedure). After 30 minutes inactivity and 5 seconds grace time.

Now if I login again, and restart the backup, there are NO problems. And as long as I produce periodic keyboard input - or other activity - on the mashine performing the backup, NO PROBLEMS EXIST, and the backup completes.

As I see it, there's a bug in TimeMachine or Sonoma 14.1's handling credentials for access to encrypted backups (on network or local media), while the displays is off, and the requirement for renewed user login is activated after a five seconds grace period (in my case).

TimeMachine has ALL the credentials it has always needed. TimeMachine can access all backups (remote or local) reliably and consistently, as long as the display is on.

A clear bug. One hundred percent reproducible.

After login, just force Time Machine to backup immediately. It will start the backup without problem. I have all the credentials required. For as long as it is needed, as long as my display does NOT turn off dure to inactivity.

The problem could probably be solved quickly, if Apple released a script, that could be run in terminal, and convinced Sonoma, that the credentials used by TimeMachine are completely kosher.

Or immediately release a security update removing the problem.

In my case, the problem can be reproduced.

In my case the problem does not exist, while doing backups, NOT lasting longer than display inactivity timeout.

In my case the problem does not exist, if the inactivity timeout is not triggered (and the need for password entry/fingerprint turns up).

Please check, if the "activity solution" also solves your problem, BEFORE tampering with backups, that may be perfectly good.

Sigh... 

I'm assuming there might be a better answer out there already, but I got mine to work. I had an older time machine drive that was showing up on my computer. When I purchased this computer a year ago, I purchased a larger backup drive. Even though I was trying to backup to my new drive, Time Machine was trying to backup to my older one. I went into Time Machine settings and deleted the older Time Machine drive. Then I was able to get an incremental back up very quickly.

(IMPORTANT INFO FOR DEBUGGING TEAM: The problem started after I "upgraded" to Sonoma. I have version 14.2.1 on my Macbook Air. Before I came up with the above fix, when I tried to do a Time Machine backup to my new Time Machine drive, it looked like it was going well. It got to 100% backed up. The error occurred because it was trying to finish/save on the old drive, which it couldn't find because it wasn't plugged in because I had selected the newer Time Machine drive. I think it is a Sonoma problem.)

Possible fix for SLOW TM backups.My TM drives were doing the same thing coming from 2014 27" iMac (Big Sur) to 2024 M3 iMac, 14.2.1, I used TM to get the new iMac up and running. My fix so far is the following:

I started a new Ext HD for TM in APFS, it's a Thunderbolt 3 drive and the backups have been FAST. It's a LaCie D2 which is powered and connected to another identical D2 via daisy chain (thunderbolt labeled cable).

The other TM drive that is SLOW is the D2 Professional USBC (black). That drive was connected to my 27" previously so it has older backups (Big Sur), that drive is what I used to get the 24" up and running. It was so slow doing the TM backups once it was used on the 24" and I wondered if the older backups had something to do with it or the Mac OS Journaled format was the problem, I did delete anything Adobe (as someone previously posted) but didn't notice any difference. *What I did do just a little while ago was change the cable to a new one that was data specific and it has HELPED speed things up (at least the first 62%)! It's not as fast as the Thunderbolt drive, but the cable helped.

If it takes a long time, even with the new cable, then I either erase the drive - leaving the Journaled format and see what happens or change the format APFS and then see what happens..

Hope this helps.

*I use (2) TM drives on my iMac the alternate every hour.

Contrary to what I reported earlier, I'm no longer seeing "backup delayed" messages for my backups to two external drives. Backups are proceeding rapidly and normally. I suspect that the problem might have been that I was connecting the backup drives via a USB-C hub that was being powered from via my M1 Laptop. When I connected my LaCie directly to the laptop, backups have been normal. My other drive is USB-3 and needs the hub. When I power the hub directly using the laptop's power adapter, backups are normal.

The only remaining issue is that SuperDuper still fails to complete clone copies to a volume on the LaCie drive. The last three lines in the SD log are:

10:53:38 AM | Info | Completed System Volume replication.  Copied 188.41 GB

| 10:55:43 AM | Info | Replicating Data Volume

| 11:09:44 AM | Info |       Volume replication failed - error 49244

| 11:09:49 AM | Error | ***ERROR OCCURRED: ****FAILED****: result=256 errno=60 (Inappropriate ioctl for device)

The good news is that with a new local SSD--starting over-- time machine worked fine. In fact is it much, much faster. I've effectively lost all my old backups (which extended for YEARS), but honestly, I don't really need them.

It's not ideal, but I understand why it happened. (I get it. The new system has a lot of security stuff which is really good--but inevitably incompatible with what's on old back ups. Much better security is important enough to sacrifice old backup copies that likely will never be used.)

But basically, the new system is incompatible with older backups. This would have been nice to have in the release notes about what has changed in the new OS, dontchathink??? It would have saved everyone a lot of time and grief to just have the new disk ready, and just do the first backup right after the installation.

So--fire whoever it is who didn't put this in the release notes.

Update to my previous post regarding the speed(s).

The Lacie D2 tbolt3 is fast, no issues - as mentioned it was a new drive (I installed a new 8tb), nothing on it except the new TM's. No issues with speed.

The Lacie D2 Professional usb-c as mentioned had older backups from Big Sur. Changed cable, still very very slow. Used Disk Utility to erase, APFS, started a new TM, the initial backup took a long time (as normal), but going forward it's speed is normal (fast).

Both drives are TM only, alternate backups hourly, no issues.

Hope the helps for now as it seems using a new/clean drive for TM is fix. Hopefully  will be able to do a workaround for people that don't want to purchase another ext HD for TM or delete their current one, etc.

Contrary to what I reported earlier, I'm no longer seeing "backup delayed" messages for my backups to two external drives. Backups are proceeding rapidly and normally. I suspect that the problem might have been that I was connecting the backup drives via a USB-C hub that was being powered from via my M1 Laptop. When I connected my LaCie directly to the laptop, backups have been normal. My other drive is USB-3 and needs the hub. When I power the hub directly using the laptop's power adapter, backups are normal.

The only remaining issue is that SuperDuper still fails to complete clone copies to a volume on the LaCie drive. The last three lines in the CC log are:

10:53:38 AM | Info | Completed System Volume replication.  Copied 188.41 GB

| 10:55:43 AM | Info | Replicating Data Volume

| 11:09:44 AM | Info |       Volume replication failed - error 49244

| 11:09:49 AM | Error | ***ERROR OCCURRED: ****FAILED****: result=256 errno=60 (Inappropriate ioctl for device)

It looks like the 14.2 update fixed my issue.

Went back to automatic backups after the update and all backups were correct and incrementally done.

Ths wasn't possible before the update.

I had the same problem after upgrading to Sonoma (14.1.1). Time Machine backups would stall part way through and just never finish. I never figured out what was causing the problem, but I solved it by formatting a new disk as APFS and designating it as the Time Machine backup destination. Starting over with a freshly-formatted APFS disk solved the problem.

My problems seem to be fixed after waiting hours for some mysterious iCloud syncing.

• iCloud was in sync before the upgrade (or so it said under Ventura).
• Without any conscious changes to my iCloud folder, after the upgrade to Sonoma there was a massive sync update.
• That sync took hours even over a 250/100 Mbit/s connection.
• iCloud syncing also "finished" many times, before it started syncing again a second later. (I took a screen video but cannot figure out how to attach it to the post.)

After this sync update was finally done, iCloud calmed down and Time Machine worked.

14.2 certainly seems to have cured my problem as it is now much quicker to access Time Machine backups.

I can confirm the problem. I have a similar problem. I have just not come around to describe that also (I sometimes need to do work on my machine, a MacBook 14 Pro M1 Pro (10CPU/16GPU 16GB/1TB) ;-)

The problem was first noticed under one of the later versions of Ventura (when backup to SSD was introduced). If Sonoma is worse or just different in behavior is hard to say now.

My main FileVault II encrypted APFS SSD is 1TB internal, and one external Thunderbolt 4 SSD (2TB), both part of the standard TimeMachine 1 hour regime. As well as a NAS based encrypted APFS backup of identical content.

The culprit seems to be the 4TB Samsung T7 Shield; several times FASTER than the 4TB 2.5 inch external HDD I used before the problem shoved up.

As I see it, both Ventura and Sonoma forces boot time SSD “content layout and consistency scanning” priority on an SSD based TimeMachine backup, and ordinary use of the computer is more or less impossible, until that scan has succeeded (seems to be an SSD only behavior). If you open an external disk, no root folder content (or content not "actively" clickable) is shown. If you try to start an application - let’s say DaVinci Resolve Studio - nothing happens, but the “waiting game rotating indicator” turns up. After a loooong time, an error message like “could not start ….” Is shown. Most ANY application shows the same behavior. From Apple or third party. Small or large.

As - ahem - soon as the TimeMacine SSD switches from “orange external disk” icon to “TimeMachine” icon, any “inactivity” problem vanishes immediately (now you only have to contend with the new, User Interface bugs in mouse handling, when clicking on filenames, folders etc in Sonoma - sigh. You never win ;-).

I suspect, that when an ordinary encrypted APFS HDD is used for TimeMachine backups (or NAS shares), scanning of these backups are postponed, until all other boot activities have completed (as should be the case with any TimeMachine drive type).

When I remove the SSD before cold boot, the problem does NOT exist. Some time ago, I tested booting with the last used HDD based backup, and the problem did not show up (at least it was not felt).

If the TimeMachine 4TB SSD is connected any time (even immediately) AFTER cold boot, it still takes a loooong time before the orange disk icon changes to a TimeMachine icon, but now it does NOT affect system responsiveness at all, and any application starts as quickly as ordinary possible (also DaVinci Resolve Studio).

My system uses FileVault II. My 4TB TimeMachine SSD is encrypted APFS (as was my 4TB 2.5” HDD before), and backups are several times faster to the SSD, compared to the HDD. No possible doubt about that. Especially when the external SSD content involves new video projects up to hundreds of GB added within a short time span, you clearly see and feel the difference.

A connected SSD TimeMachine backup equals horrendously slow cold boots, with a virtually unusable computer, until the TimeMachine has been “digested”, and the SSD icon switches to “TimeMachine” icon.

My Mac Mini M1 16GB/1TB (also FileVault encrypted) with external APFS 1TB Thunderbolt SSD, also runs TimeMachine 1 hour regime to NAS share and local disk, but the local 2TB APFS encrypted HDD (veeeeryyy sloooow 2.5”) does not exhibit the same behavior either (whether with Ventura and now Sonoma - same versions in use on MacBook 14 Pro). Cold boot does not feel hampered.

The statement "Apple just works" could truly be "retired" to history now - sigh ;-)

Regards

Hi,

The problem is that seems Time Machine has changed. The solution was just remove the previous backups, or use a new destination folder, then start a new chain of backups from Sonoma.

When creating the new one, choose if want encryption.

I also had the TM issue but i my case the icloud backup was not completed, therefore Apple support said wait for this. Make a new tm backup.

Sorry didn't work so i downgraded back to Ventura. Now everything is ok.

So my advise (heard from others) wait for vers .2 or .3

I downgraded to ventura. Not having reliable backup is a no-go. And of cause i use 3party ** also -not icloud which also is without control.

I did though a clean Sonoma install and time machine worked just fine.

But then there are many other irritation on the Sonoma. I don't consider any real added values yet.

A Sonoma tm will also work with Ventura

Called Apple support but this is a joke they live in dinial.