Situation: I have a system that spends most of it’s time running as a server but occasionally I need a GUI so KDE is installed. 95% of the time I don’t want KDE or even KDM eating resources. When I want it, it’s easy enough to launch from a command line on demand. How do I remove it from the start up. Easy way is to start deleting files from the rc.* directories. The approved way appears to be the following:
sudo update-rc.d -f kdm remove
To add it back:
sudo update-rc.d kdm defaults