Is there a way to easily find "purgeable" files?
Recent versions of macOS have started reporting storage values in some places by taking account of "purgeable" files. I have a reasonable idea of what types of files fall into that category but no explicit knowledge of exactly which files, nor whether that purgeable space will be automatically made available if needed.
I'm looking at a particular instance this morning where I have an SD card that I use for slow access files for my MBP and which is (definitely) not my boot drive. Supposedly there is about 40GB of purgeable space but that number doesn't match in particular to any specific folder that I can tell (eg. I have 28GB of Library/Application Support/Apple/AssetCache).
a) I can't find any attribute within Finder search for "purgeable" to allow me to search - is there a way?
b) Given this is not the boot disk will there be any auto delete of these purgeable files when needed?
What does disk utility tell you for the volume with respect to purgeable?
I entered the following in the terminal and found delete-d(aemon)
iMac:~ alex$ apropos purgeable
deleted(8) - The purgeable space / cache management daemon
… and that gave me deleted(8) which, as per the man page is has its governing bodies (plists) as it were, sitting at /System/Library/CacheDelete.
Summary of deleted description
deleted is a system daemon that keeps track of purgeable space via registered services.
I would be starting my investigation from here, google and developer.apple.com would be reasonable starting points of course.
I reckon there are daemons working away in other parts of the system making similar or relate memory/space management decisions but deleted seems to me to be the big dog.
The question is a fascinating one.
Relative to the Info Window screenshot, Jason Snell took a stab at it. The article is a couple of years old, unless something dramatic has changed it should prove learned.
By the way, this was fun:
- Launch Console and select the computer device from the console sidebar
- Open "About this Mac" menu item
- Click Storage
- Observe "deleted" process suddenly populate the console window in a rather dramatic way
In my case 1444 messages with deleted were spawned.
I am sorry if I am not answering your question entirely and for my sporadic response but I am rather ignorant of this myself. I do hope this kickstarts your knowledge adventure. It's an interesting question that deserves some exploration. I wish I had a little more time to devote to it but I hope there are some bits of inspiration.
Below is a screenshot of my 3 or 4 year old MBA which has a fairly small SSD, a space where purgeable data really makes sense. Go to it via About This Mac and then click on manage.
It would appear to me that each of the items in the sidebar represent locations where purgeable items exist and I think it is, at least in this location, being used loosely as the list is an interpretation of data that can be discarded without fear or permanent loss because these files can always be recreated later via another download, be it IMAP, App Store purchases or similar, in some cases it may not come back like the items in the trash unless there is a time machine backup. I think you get the idea but I am not sure if this answers the question entirely. Still I would rather put this here because it could be a partial reply. Of course there is ~/Library/Caches as well which I figured was a given but it's best to be vocal about it I suppose.
I'm just creating more questions.... when I run OmniDiskSweeper on that 128GB SD card it reports that 149.3GB is used!!
In my experience that sort of inconsistency happens when there are hard links - and I suspect the cause of those is going to be the folder with iMazing backups