time machine won't back up after I installed Sonoma

mikejohes wrote:

If your Time Machine backups started failing after you installed Sonoma, which I assume refers to a software update, application, or a new operating system...

Hmm, you may want to double-check the AI results for accuracy. Sonoma would be the latest macOS operating system. The OP could have either updated to the latest release or upgraded from an earlier macOS version. This, of course, could have precipitated the issue with Time Machine.

Not faulty anyone for using AI, regardless of what AI tool they want to use ... just please verify the results for accuracy.

How can I tell AI was involved here? Statements like these were a strong clue:

• "Reinstall Sonoma: If it's a software package, try uninstalling and then reinstalling it. If Sonoma is an operating system update, consider reinstalling the OS." << Sonoma may be software; however, it is not a simple application. It's an operating system. Although reinstalling the OS is one potential solution, it should only be considered as the last resort.
• "Contact Support: If Sonoma is a third-party software, reach out to their customer support for troubleshooting assistance as there may be known issues with Time Machine." << Sonoma & Time Machine are integrated components. Sonoma, would not be a third-party software here. Apple provides both of these ... so the more accurate solution would be to contact Apple Support in this case.

Please don't take my comments as derogatory. I simply want to point out the shortfalls of relying on AI ... and the importance of "fact-checking" its results.

If your Time Machine backups started failing after you installed Sonoma, which I assume refers to a software update, application, or a new operating system, the issue could be related to compatibility or a system-level error rather than a problem with your backup disk.

Here are some steps you can take to troubleshoot the issue:

Check Compatibility: Ensure that Sonoma is compatible with Time Machine. Sometimes, system updates or new installations can affect how backup services run.

Software Updates: Make sure that you have all the latest updates installed for your OS and for Sonoma itself. An update could resolve the issue if it's known to the developers.

Disk Utility: Use Disk Utility to check your backup disk for errors. Open Disk Utility, select your backup disk, then click on "First Aid" to start the disk repair process. This can fix problems related to the disk's formatting and file structure.

Time Machine Preferences: Sometimes, removing the disk from Time Machine preferences and adding it back again can solve the issue. Go to System Preferences > Time Machine, click on "Select Disk," remove your backup disk, and then add it again.

Console Logs: Check the Console app for any error messages that could give you more details about what's going wrong with your backups. This could provide specific clues on whether the issue is with the disk or the OS.

Alternate Disk: If possible, try using another disk to see if Time Machine can successfully back up to it. If it can, the problem may be with your original backup disk.

Reinstall Sonoma: If it's a software package, try uninstalling and then reinstalling it. If Sonoma is an operating system update, consider reinstalling the OS.

Contact Support: If Sonoma is a third-party software, reach out to their customer support for troubleshooting assistance as there may be known issues with Time Machine.

External Factors: Ensure that the backup disk has enough storage space and that you're using the correct format. Time Machine requires disks to be formatted as Mac OS Extended (Journaled) unless you're using APFS for macOS Catalina or later.

Upgrading to macOS Sonoma should not be the sole reason that your Mac is not successful backing up with Time Machine. There could be a number of reasons, but without a lot more information, it would be difficult to tell you what those are.

For example, what error messages are you seeing? What have you tried, so far yourself, to resolve this so that we don't offer potential solutions that may not have already worked for you?

What version of macOS was your Mac running before you upgraded to macOS Sonoma? Which exact model is your Mac?

Were you backing up to a Time Capsule or to an externally attached USB drive?

A sledgehammer option is to backup all of your data files you wish to keep to different backup Media using a program like SuperDuper! which does have a free version. Next erase the old Time Machine disk and then start TM and it will initially do a full backup and afterwards will do the timed backups as normal. If the problem still exists then it wasn't the disk.