Does consolidating library do
When you consolidate, copies of any files that were outside of your i Tunes Media folder are added to your i Tunes Media folder.To save space on your hard drive, you might want to delete the original files after you make sure that the copies are in your i Tunes Media Folder.Apple makes no representations regarding third-party website accuracy or reliability. Though we store more and more of our music online these days, a hard-copy backup is still the gold standard for keeping your data safe.Note: After making a copy, it is a good idea to move the copied folder to an easy-to-find location that is separate from any folder you plan to make changes to (like the Music folder).This copied folder should be deleted immediately after it is no longer needed because it takes up extra space on your computer's hard drive unnecessarily and could cause confusion with your most current i Tunes folder.
When I go to open the library on the laptop fromt the ext drive, it's missing about 18 files that are still being referenced on the macpro.
You should also redownload any previous purchases (music, movies, TV shows, etc.) and turn on automatic downloads for future purchases.
i Tunes in the Cloud is not a backup service, and having a local copy (a copy downloaded to a computer) is the only way to back up your purchased media.
To ensure that long time, depending on how big your i Tunes library is.
So, sit back, relax, watch a movie, or whatever you do to pass the time.