Partly in the interest of keeping things simple and because a friend has given me a stand alone CD burner thus making freeing up the CD drive a moot point I've successfully run the mkimage script and am kind of glad I didn't try to divide that 10GB partition that I set aside for it - The image as it stands now is well over 4GB and will grow as I customize and add things to the basic Knoppix setup - better some growing room! Thanks to all who offered advice and answers when I needed them.