One of the features of APFS is supposedly a cache for total size of directory trees. As far as I remember, it is something the OS decides to turn on or off for

One of the features of APFS is supposedly a cache for total size of directory trees. As far as I remember, it is something the OS decides to turn on or off for different folders. It’s wasteful for /tmp, for example, because it makes file creation and deletion slightly slower. I’m not entirely sure if du would want to tap into that. A lot has changed in MacOS, and it’s not entirely clear if we still have a universal definition of “file size”. You can let iCloud store large files now, for example, truncating the local file when it is rarely accessed. Don’t remember the exact name, sorry. There is a MacOS-native way to explore recursive size, by the way: about this Mac -> storage -> manage -> documents -> file browser. This is limited to your user folder by default, but you can just create a soft link to take you to /