Can we trust the figures the Finder provides for used and available space on a volume? What does it count as purgeable?
Disk Utility
When the Finder works out how much space is available on disk, what does it count as being “purgeable”? The answer may surprise you.
The Finder reported free space had risen by over 80 GB, that’s more than 50%. It looked like something had wiped some of my media libraries.
Here’s an APFS (Encrypted) volume that isn’t encrypted, and an unencrypted volume with FileVault active. Something must be wrong.
Should you run First Aid on every volume, then each container? And why can it return status 65? How can you work around that?
Have you ever tried running First Aid on an APFS volume and been told it failed with status 65? It’s time for that to be fixed, so we can check and repair disks properly.
Plain read/write (UDRW), sparse image (UDSP), and sparse bundle (UDSB) compared for storage efficiency, performance, and convenience.
All you need to know about the sparse RAW disk images used inside lightweight VMs on Apple silicon Macs.
In Monterey and Ventura, regular read-write UDRW disk images can now be APFS sparse files, and work more efficiently than sparse images or sparse bundles.
Disk images originated in the 1960s, and are still valuable tools in modern macOS. They have their limitations, though, and in some cases should be replaced by APFS volumes.
The Eclectic Light Company 