One good way would be the classical linux-like approach: use rsync from the Terminal. Rsync is an application designed for file transfers preserving anything from timestamps over access rights to other metadata. And it's really straightforward to use, since Apple was smart enough to include it in OS X :)
The basic syntax is as follows:
rsync -aP <source> <destination>
The -a stands for archive (which means, preserve time stamps, access rights and other metadata) and the P stands for progress (which means show progress during transfer). This will create an exact copy of source over to destination which copying by Finder would not.
If you never ran a command from a Terminal, don't fear, it's not hard! And in this case, there isn't really something you could do wrong.
- First, open the Terminal from Applications/Utilities, or use Spotlight.
- Then type in the start of the command:
rsync -aP. Make sure to include two spaces: one after rsync and one after -aP.
- Then drag the source folder from Finder into the Terminal window (probably
/Volumes/MEDIA_2TB/iTunes/ in your case). This will insert the path of that folder into the Terminal.
- Now type a space after the path, so that the source is separated from the destination you'll drag in now.
- Drag the destination folder (probably
/Volumes/MEDIA_4TB/iTunes/ in your case) over to the Terminal window. If the iTunes folder does not exist on your drive yet, create it (e.g. using Finder).
- Make sure that both the source and the destination path end with a
/. Otherwise, the iTunes folder from the original hard drive would be integrated into the new iTunes folder on the new hard drive, resulting in two iTunes folders nested within each other (wouldn't be too bad, though, but unneccessary ;))
- Hit enter to run the command. Now you should see all your files rush by on the Terminal and the new iTunes folder on the new hard drive should get populated.
That way, you'll create an exact copy of your iTunes data including all metadata. Are you sure that the current version of your .itl files are still in your Music folder? I haven't seen a case where these were located outside the library folder. Check the modification dates on these files to check if they are really the current version. If they are, you should use rsync again to copy them over to your hard drive. Just use ~/Music/iTunes/ as a source now, it will overwrite any files already existing in your destination if the new files you are moving are newer, and all other files will be kept in place.
