If you want to copy a dual layer DVD to a single layer one in Linux, you will very pleased to know K9Copy. This is a nice utility that removes unwanted extras and/or requantizes the main title while preserving the menu structure.
As it isn't available in the Livna repository, I created a RPM of it for Fedora. Check the K9Copy RPM link in the nav bar.
Copyright © 2007 Gustavo M. D. Vieira