I decided to move my iTunes Media folder to an external drive. I followed the article in Macworld Christmas 2011 (p.71), "Move your iTunes Media folder", to the letter.
Unfortunately iTunes did not move my entire library; of over 30,000 files, it left more than 5,000 alone. These tracks were then marked as 'lost'.
When this happens, there's no going back. If you don't mind losing all your ratings etc., you can find which items are missing & drop them on iTunes to start again. But if that isn't an option, you have to locate each track — an estimated 48 hours work in my case.
You can either locate the files in their original locations, & then consolidate the library (which copies them to the new Media folder), or you can move them first & then locate them in their new locations. That's slightly quicker, so that's the route I took.
The problem is that there doesn't seem to be a shortcut to locating the "missing" tracks. They're all in the right places, & nothing has changed, but once iTunes marks them as missing the only way to locate them is individually (under certain circumstances you may be asked if iTunes should look for more files in the same folder, but as many people have remarked, it doesn't actually do so when you click on 'Okay').
I tried looking for scripts that could automate this task. I downloaded three scripts from Doug's AppleScripts for iTunes, namely "Fix Missing Tracks", "List MIAs" & "iTunes Track CPR". The latter was the most promising, since it should in theory look for all selected missing tracks & locate them in the new Media folder, thereby locating them. However, it kept giving the self-contradictory result "Recovered: 0 / Still MIA: 0".
So… any suggestions? Any more up-to-date scripts to address this issue?