Is there a difference between launching an app from /Applications vs /System/Volumes/Data/Applications? [duplicate]
I noticed that since updating to macOS 10.15, I get duplicate search results for some apps (due to the new read-only filesystem).
If we take Spotify as an example, is there any difference between launching either of:
/Applications/Spotify.app/System/Volumes/Data/Applications/Spotify.app
or is the second option semantically equivalent to a symlink?
Clarification My question is not why there is a second folder, or why I get duplicate search results. My question is whether there is any difference in behaviour when looking at how apps from the two file locations are treated by the system (for example, does macOS impose additional restrictions on apps launched from /System/Volumes/Data?), or whether they can be treated as identical.
Solution 1:
Treat them as identical. There is no functional difference in finder or another program opening either path to the same Application bundle. You have only one Spotify app despite it showing up at two distinct POSIX paths.
It is not a sym link but a hybrid combination of two filesystem links that is presented as the path /Applications on Catalina.
I would say the closest analog would be a hard link on OS prior to Catalina, but firm links are new to Catalina and are not the same as symbolic or hard links.
You’ve chosen the strangest folder in existence on Catalina since it’s a hybrid / illusion as named in the most superb technical discussion on this idea I’ve seen:
The old folder containing main apps, which used to be /Applications, now contains a mixture of apps from two different folders, /System/Applications, which is on the System volume and contains Apple’s bundled apps, and the Applications folder on the Data volume, which would otherwise be found at /System/Volumes/Data/Applications. When you install your own apps, they automatically get placed in the latter folder, as it’s the one which you can write to. When you view the /Applications folder in the Finder, though, you are actually seeing the combined contents of both folders, an illusion which is created by the firmlink at /Applications and the Finder.
- https://eclecticlight.co/2019/10/11/macos-catalina-boot-volume-layout-revised-for-10-15-release/
Apple technical documentation is also plentiful, but not as detailed or readable as the Eclectic Light blog post.
- What's /System/Volumes/Data?
Solution 2:
Catalina introduces a new way of managing the storage of the core OS/applications vs "user space." Everything that is "stock" is kept segregated from the "user" space, which in turn is now identified as "Data" and is mounted at "/System/Volumes/Data." This can be seen in Disk Utility's "volumes" view.
Finder's Applications folder basically is an amalgamation of /System/Applications as well as anything installed in 'user' space, in this case "/System/Volumes/Data/Applications". Running an app from either location makes no difference as they are the same file.
However they are functionally different insofar as the user should only be able to modify items within the confines of /System/Volumes/Data/Applications. Anything installed by a user will end up in that location as well (for example try ls /System/Volumes/Data/Applications, and compare with /System/Applications).