A brief start with MFS for 400 KB floppies, followed by HFS intended for the first hard disks, upgraded to HFS+ in 1988, and followed in 2017 by APFS for all the OSes.
Time Machine
How do clone files and sparse files cope with being backed up and restored? Can they save space in iCloud Drive? Some of these answers may surprise.
How DAS gathers its budgets and loads lists of activities. When rescoring permits, it then dispatches the process to initiate backup. Re-scheduling has changed in Sequoia, as shown here.
There’s normally more than 500 background activities, like Time Machine backups and XProtect Remediator scans, waiting for dispatch in the list maintained by DAS. How this works.
How snapshots are created from a volume in around 0.01 second, why they will grow in size over time, how they can only be of complete volumes, and can’t be edited.
Does your NAS need faster storage or a faster network? If you were to improve those, would throttling limit the performance of backups?
It’s well known that writing Time Machine backups to storage is throttled to slow them down. What’s the point of using faster SSDs that are more expensive if macOS stops them from being fast
macOS logs may only last a few days, or even hours, into the past. Here’s a quick and simple way of browsing the log from weeks, months or even years ago.
When and how to use Migration Assistant to move apps, settings and documents to a new or previously owned Mac. Also how a Mac can claim an old Mac’s backups.
Understand how TM backs up and how snapshots work to minimise the size of local snapshots and backups, and the time they take. How to ensure files in iCloud Drive are backed up properly.
The Eclectic Light Company 