Sonoma’s changes to iCloud can result in very large and protracted syncs, that can block Time Machine backups from completing. Here’s what you can try, and what you shouldn’t do.
backup
Do you need to back it up when the problem is minor? Should you erase its internal storage? Anything else you need to do?
Using local Time Machine backup, iCloud Recovery, and saved versions to recover previous and current versions of files in iCloud Drive, and their limitations.
How to plan and assemble faster backup systems for Time Machine, whether to change I/O policy, and how to minimise their size using exclusions.
Save space on your storage and backups by removing all copies. But does it work if they’re APFS clone files? And does that housekeeping utility detect clones for you?
T2 and Apple silicon Macs always encrypt the Data volume in internal storage. So why bother with enabling FileVault? And can you do that on external bootable disks?
Detailed account from the decision to start making an automatic backup to its final reporting and completion, for Ventura 13.2.1 to local storage.
You’re running bit short of disk space, so put tens of GB of old files into the Trash, then empty it. Why doesn’t the amount of free space increase?
While macOS uses DAS-CTS to schedule hundreds of background activities, third-parties normally use launchd. Comes with a full diagram explaining DAS-CTS.
Backing up with Time Machine to a NAS or other network storage is different. Here’s an account of how it creates and handles sparse bundle storage in Ventura 13.2.
The Eclectic Light Company 