This has been quite overdue, as I have been wanting to disable
ntpupdate since the Hoary release. What is
ntpupdate anyway? It’s the program that synchronizes your system time to an ntp server. NTP is a protocol for synchronising the clocks of computer systems over packet-switched, variable-latency data networks. Since Ubuntu defaults to an ntp server somewhere in the www, and that it will attempt to sync on boot, it causes your machine to go through a much much longer startup process if an internet connection is not available at boot time.
As I am lugging my lappy around a lot and I have not much of a need for the program, I knew I had to take it out and save me minutes of boot time. Ealden taught me how to remove
ntpupdate, and I suppose we can change the arguments to remove other programs as well.
$ sudo update-rc.d -f ntpdate remove
update-rc.d will remove any system startup links for
/etc/init.d/ntpdate, or any instances of such in the different run levels. Usage is as follows:
usage: update-rc.d [-n] [-f] <basename> remove
update-rc.d [-n] <basename> defaults [NN | sNN kNN]
update-rc.d [-n] <basename> start|stop NN runlvl [runlvl] […] .
-n: not really