How can I redirect my iTunes library to an external hard drive?

Solution 1:

This article may help you.

Managing your iTunes Library on an External Hard Drive

Solution 2:

Okay, here's my brief summary for users of iTunes 9:

I've purchased a new SSD system drive and wanted to migrate my old iTunes Media folder (~/Music/iTunes/iTunes Music) to a harddisk. At the same time I wanted to rename the folder from iTunes Music to the new name iTunes Media. Apart from that I also wanted to keep the iTunes database (referencing the media files) on the system SSD (for better performance). Here's how I accomplished this:

1. Create a new, empty media folder on the 2nd harddisk. In my case /Volumes/WesternDigital320GB/iTunes Media.
2. Go to iTunes Preferences->Advanced->iTunes Media folder location and change it to this new location. iTunes now updates the file paths in its database to the new location but does not copy the files.
3. Then go to File->Library->Organize Library... and select Consolidate Files and click Okay. Now iTunes copies the files from ~/Music/iTunes/iTunes Music to the new location.
4. Verify that the contents of both directories is the same. Afterwards you can manually delete the media files at the old location (~/Music/iTunes/iTunes Music).