brew install fclones
cd ~
fclones group . | fclones dedupe
I've used fclones before in the default mode (create hard links) but this is the first time I've run it at the top level of my home folder, in dedupe mode (i.e. using APFS clones). Fingers crossed it didn't wreck anything.
< You can also create [APFS (copy on write) clones] in Terminal using the command `cp -c oldfilename newfilename` where the c option requires cloning rather than a regular copy.
`fclones dedupe` uses the same command[1]:
if cfg!(target_os = "macos") {
result.push(format!("cp -c {target} {link}"));
Nice, also compression at file system level can save a lot of space and with current CPU speeds is completely transparent. It is feature from HFS+ that is still works in APFS, but is not officially supported anymore, what is wrong with you Apple ?
This tool to enable compression is free and open source
Also note about APFS vs HFS+, if you use HDD e.g. as backup media for Time Machine, HFS+ is must have over APFS as it is optimised only for SSD (random access).
Not so smart Time Machine setup utility forcefully re-creates APFS on a HDD media, so you have to manually create HFS+ volume (e.g. with Disk Utily) and then use terminal command to add this volume as TM destination
