Symbolic links farm


Symlinks in /etc/rc<runlevel>.d/ pointing to the scripts that should be run (usually placed in /etc/init.d/)
Symlinks start with "S" (start) or "K" (stop)
Two digit number to select position in queue
ABSOLUTELY NO CONCURRENT RUNNING OF SCRIPTS

Runlevel S does not run any scripts, those are run at startup
Runlevel 0,6 run all scripts with "stop" actions, even S##* scripts

The default System V init script system is a powerful, comprehensive, modular, extensible BIG MESS!