Keep tabs on all your Libraries.

It can be a complex job keeping tabs on all your Libraries if they are spread over several hard dives.

A very useful free app is Final Cut Library Manager.

https://www.arcticwhiteness.com/finalcutlibrarymanager/download/

The basic version, which should suit most amateurs is free but if your requirements are more complex, you can add paid options.

The app was created shortly after the introduction of Final CutPro X by a contributor to this forum.

Note that I do not profit in any way from promoting this app . . . it's just that I was one of the first users and found it very helpful.