I have been playing around with chmod, chown, setfacl and special bits trying to get multiple system/full users in same group correct access permissions to my media collection.

But I've messed it up somehow and now I'm having weird problems that are hard to track.

I would like to set my whole collection back to the defaults.

What is the best way to do this?

One problem I've had when making changes to so many files is the process seems to go forever without completing. Eventually it gets killed so my filesystem has variable attributes throughout. how can this be worked around?

I want everything to be owned by myuser, group media, everything else default I will sort it from there once I have a fresh slate.

And is there a way to backup these attributes only? I don't have enough storage to backup the files themselves.

It is Debian with ext4 filesystem.

Edit to add: Media collection is on its own separate drive/filesystem; this has no impact on anything else on the computer.