What you need to know about the HFS+ file system, so you can understand error reports and how to repair it using Disk Utility and other tools.
volume
Apple says that if you run First Aid on a disk, each of its volumes is checked too. Is that really true?
One new tool to list capacities on mounted volumes, the other to deliver detailed information on keychains.
If something goes wrong with Catalina’s boot Volume Group, it seems there’s no way to repair it, or change the Data volume. Or is there?
APFS adds 6 volume roles, including one which supports Time Machine backups. And per-file encryption is coming.
What happens when you copy a large file to the same volume, or duplicate it, on the same APFS volume? Here are the answers.
The volume should only be half full, but installers and other software complains there’s insufficient free space. What to do.
macOS Catalina is the first version of macOS which boots not from a single volume, but from two: […]
The Finder, Disk Utility and Terminal show disks and volumes differently, according to their function. This can appear confusing in Catalina until it has been explained.
Updated for 10.15 release, with a clearer explanation of how Catalina’s new boot Volume Group works in practice, in the Finder and Terminal.
The Eclectic Light Company 