While macOS uses DAS-CTS to schedule hundreds of background activities, third-parties normally use launchd. Comes with a full diagram explaining DAS-CTS.
backup
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.
How running a background task takes a tiny fraction of second, although the task itself takes seconds or minutes, and why it’s run on E cores.
How macOS schedules tasks like making automatic Time Machine backups, from property list to transactions between DAS and CTS.
The story of how Mac OS X went from cron, to launchd, and ended up with Duet Activity Scheduler, to schedule background activities like backups.
Virtual Machines for lightweight virtualisation on Apple silicon Macs rely on sparse files. Here are tips to ensure they stay small and don’t explode to full size.
Excessive CPU use by mds_stores is a common cause of sluggish performance. Explains what it does and what you can do bring it under control.
Has Ventura brought any relief from Disk Utility’s inability to run First Aid on Time Machine’s backups, and what about changes in Time Machine itself?
In the past, a second, cloned bootable volume on a separate disk was a great advantage. Cloning has become harder, and Recovery better. What should you do now?
Copies, clones and backups are three different things. Here their differences are explained with examples from APFS and modern macOS.
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