Here are typical layouts for the iTunes folders:
If you have upgraded from version 8 (or earlier) to iTunes 9 (or later) at some point, then your media folder (everything inside the red outline) may still be called *iTunes Music* instead of *iTunes Media*. The extra
Music folder inside the media folder is used if you have allowed iTunes to *Upgrade to iTunes Media Organization* (iTunes 9) or used *File > Library > Organize Library > Reorganize files in the folder "iTunes Media"* (iTunes 10). Depending on your choices for *Keep iTunes Media folder organized* and *Copy files to iTunes Media folder when adding to library* plus a little bug in which one build changed the name of the file storing the choice of layout it is quite easy for some of your files to be organized according to one layout and some the other.
So... if you use the kb suggested method to move the media folder then you need to choose your new media folder on the external and consolidate everything to it. This copies all content inside the red box to the new folder. If your library was in the iTunes 8 layout and you also want iPod Games & Mobile Applications on your external drive then you need to *Upgrade to iTunes Media Organization* (iTunes 9) or *Reorganize files in the folder <Media Folder Name>* (iTunes 10). Only when you've checked that media, iPod Games and Mobile Apps are all being referenced on the external drive is it safe to first move those folders from their current location on the internal before testing the library again and then deleting the redundant folders.
The library files, Album Artwork and Previous iTunes Libraries folders should be left where they are, although you can probably delete all but the latest of the backup libraries in the Previous... folder.
If you want +even more+ room on your internal drive it is also possible to relocate the library files on the external drive. Details on request.
tt2
PS - I've no idea what
qsdata is, I've never seen it before.