My wife and I are inveterate music collectors and traders (of legally recorded shows by artists who permit this, natch) and have finally run out of space on the external (firewire) 250 GB hard drive that contains our iTunes library.
The specifics of the gear: Mac G4, 2 LaCie 250 GB HD (firewire), iTunes 6.0.2 (23)
How can I share my iTunes library across multiple hard drives?
Thanks in advance!!
In “Preferences” goto Advanced.
There is a checkbox next to “Copy Files to Itunes Music folder when adding to library”
simply uncheck that box.
Subsequently, you can spread your library acrosss as many locations as you desire because itunes won’t be trying to keep a copy of everything in one folder.
There will be zero change to playback, library data, or anything else.
Since Macs now have Unix guts, do they allow symbolic links?
That’s how I have handled the very same problem on my aging Linux machine that holds my mp3 collection. The music appears to all be under one tree of folders, though different branches of that tree are symbolic links elsewhere.
Mount points offer similar behavior, though with a little bit more work.
I’m certain that the little checkbox mentioned by xiix is really the correct and easiest answer, but I’m curious about Mac support for symlinks and mount points anyway.
Yep. But xiix’s answer is much easier. (And doesn’t require using the big scary Terminal.app! 
)