Prior to Sonoma, I set Time Machine to do hourly backups. They did not seem to interfere with the computer usage. After Sonoma, the backups slow down the computer and TM seems to be always backing up. I changed the setting to daily. One time I opened the settings window while it was preparing for backup so I could see the status messages. They showed a really large amount of data to backup. I know this could be from some system update, so I tried something to get a real feel for what is happening. I forced a backup at around 11 PM one night. Next day, I saw that it took almost an hour. After checking that I forced another backup; this is about 9 hours later with the computer sleeping the whole time. As it was preparing, I saw that TM found 13,000 files had changed. How is this possible?
iMac from 2019; Sonoma 14.2.1, 3.6 GHz 8-Core Intel, 16GB memory
Any information is appreciated.
Eclectic Light Company seems like a nice resource. I bookmarked it for future. The referenced article is about iCloud sync causing problems. Finder shows that my iCloud is synced to my Mac; i.e., there is a checkmark beside it in the Finder sidebar. I will try the other accounts login to see if that helps.
(off-topic:) Howard and Eclectic Light Co are a fantastic resource. Be sure to check out his numerous, free software tools. I use SilentKnight on every system I touch to check if the hidden malware apps are updating correctly. His art postings are also fascinating.
Ant drive will be faster after wiping it. Creating and deleting APFS snapshots every hour will fragment data on the drive. The performance hit should be minimal for an SSD, but can be quite a lot for an HDD (you don’t say what your backup device is).
As for the original problem, I don’t know. But I do know that the count of files backed up can be misleading because Apple makes extensive use of “package” files, which are actually directories. Minor modifications to a package may result in its entire content be reported as “need to be backed up” even though when the backup actually happens, it may only copy the files within the package that have actually changed.