It is simply a service to update DNS. There is no need for it to run in the background. Therefore it's launched on bootup in runlevel S. But just to be sure, I installed it on one of my computer and guess what, no more DNS ! I don't know about you but since it doesn't do me any good I prefer to remove it rather than learn how to operate it (at least for now).
Here is short explanation from <http://ubuntuforums.org/showthread.php?t=89491> : runlevel S: the first runlevel in boot process. /etc/init.d/rcS script will be invoked to start and all the processes underneath /etc/rcS.d will be executed. runlevel 1: the single user mode. All processes underneath /etc/rc1.d will be executed. runlevel 2,3,4,5: in debain system, the multi-user env, may not may not include GUI. The same, processes under each of the corresponding dirs will be run. runlevel 0: computer shutdown. runlevel 6: computer reboot. -- No DNS at computer start https://launchpad.net/bugs/54115 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs