If you love music, movies, TV shows, and podcasts there’s a good chance that your iTunes Media folder (formerly called the iTunes Music folder, and yours might be called that if you’ve been using iTunes for a long time) has swollen to the point where it’s pushing up against the bounds of your hard drive’s capacity. In such cases you need to move your media to a more expansive drive. Here are the steps for doing just that.
via macworld.com