If you notice that the Available Disk Space and Free Disk Space Device Facts are showing different values, this is expected behavior — the two facts measure different things.
- Free Disk Space — the amount of space that is immediately usable.
- Available Disk Space — free space plus purgeable space. Purgeable space consists of files that macOS can reclaim automatically when additional storage is needed (such as cached iCloud files, Optimized Storage items, and similar data).
Because Available Disk Space includes purgeable space that may not yet be reclaimed, it will often report a higher value than Free Disk Space. For monitoring purposes, Free Disk Space is the more conservative and reliable indicator of truly usable storage on a device.
Recommendation: Monitor and maintain a minimum of 20GB of free disk space on managed devices to avoid potential system slowdowns or unexpected behavior, particularly on devices running resource-intensive workloads.