All about xattrs: their origin, where they’re stored, how they’re named and typed, how to find and work with them, and their common problems.
HFS+
Explaining inodes, names, dates, permissions, file types, and specialised attributes used for iCloud.
Looking in more detail at newer tricks used by APFS on the data of files: sparse files, which can squeeze vast empty files almost to nothing; file clones; and compression, opening up in Big Sur.
Disk structure diagrammed for comparison, from the partition table, to HFS+ and APFS volumes, with further references.
What you need to know about the APFS file system, its containers and volumes, so you can understand errors and how to repair them.
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.
What you need to know about disk formatting using the GUID Partition Table (GPT) to understand its problems and how to repair it.
How to store a 400 GB sparse bundle on a volume which only has 200 GB free space – provided that you don’t actually use the space that isn’t there.
How to hide text so that it can’t be searched or analysed, and how file naming almost brought APFS down.
Time Machine has been using snapshots since High Sierra. How can it then use them to make backups to APFS volumes in Big Sur?