What happens when a Mac runs out of free space in the container of its boot volume group? This shows what you can expect to see, and what happens in the log.
purge
Caching to disk improves performance, but cached data are optional and may be purged when additional free space is needed. This explains how that’s performed by the deleted service.
Further tests on two volumes with over 90 GB purgeable space. One took almost 30 minuted to become available, the other never got there at all. The log reveals who was responsible.
All APFS volumes in a single partition/container share its free space. How can that be measured? How much could be purged, and how do special file types affect it?
Where are all those purgeable files? Two updated utilities to help you find them: Precize and Sparsity, which will crawl folders checking which files are purgeable, sparse or clones.
Performed by CacheDelete, it first looks at a wide range of macOS caches, and only at the end purges snapshots, to free up space when it runs short.
Although my Mac has 6 GB of memory, I have had to use the purge command with depressing frequency since OS X 10.6, before quitting anything, particularly Safari.
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