HFS+ compression is a technology introduced in 10.6 Snow Leopard that allows files to be compressed on disk invisibly to the user. They are decompressed transparently at the time they are used/read. This was the reason Apple could reduce the required space for installation with 10.6.
So with APFS and it's in-place-conversion of HFS+ disks, it seemed that it would have to honour any HFS+ compressed files that existed. My tests show that it indeed does (I used afsctool to list HFS+ compressed files on my disk).
You can also still HFS+ compress files on APFS, for example using ditto with the --hfsCompression option.
Hopefully Clusters will be updated or a new tool will be released to allow users to continue to use HFS+ compression on APFS.
Anyway, this was a PSA to let people know that APFS supports HFS+ compression. Rejoice!
Third party software allowed users to use HFS+ compression on files of their own choosing. Clusters is the app I use to compress other files on my drive in the background and it has saved me over 150GB in the time I've been using it.
So with APFS and it's in-place-conversion of HFS+ disks, it seemed that it would have to honour any HFS+ compressed files that existed. My tests show that it indeed does (I used afsctool to list HFS+ compressed files on my disk).
You can also still HFS+ compress files on APFS, for example using ditto with the --hfsCompression option.
Hopefully Clusters will be updated or a new tool will be released to allow users to continue to use HFS+ compression on APFS.
Anyway, this was a PSA to let people know that APFS supports HFS+ compression. Rejoice!
