The library scanner has a feature that is supposed to detect 'moved' folders and files. If your external music HD is mounted on one computer at /media/foo and on the other computer it's /media/bar then if nothing else changed and you open Mixxx with --settingsPath pointing to your settings folder that you brought over from the first computer, change the Library path in the Preferences to /media/bar, then hit re-scan. Mixxx should be able to detect that every file has moved and re-attach the files with their orphaned metadata (beatgrid/waveform/hotcues/playlists/crates/artist/title/album/etc).
I've never tried this though, but I think it should work.
@RAWRR -- yep, everything you said is correct.
The library scanner has a feature that is supposed to detect 'moved' folders and files. If your external music HD is mounted on one computer at /media/foo and on the other computer it's /media/bar then if nothing else changed and you open Mixxx with --settingsPath pointing to your settings folder that you brought over from the first computer, change the Library path in the Preferences to /media/bar, then hit re-scan. Mixxx should be able to detect that every file has moved and re-attach the files with their orphaned metadata (beatgrid/ waveform/ hotcues/ playlists/ crates/ artist/ title/album/ etc).
I've never tried this though, but I think it should work.