Ubuntu runlevel service startup
From thelinuxwiki
Command line tool to manage services / Ubuntu runleve
l
update-rc.d automatically updates the System V style init script links /etc/rcrunlevel.d/NNname to scripts /etc/init.d/name. These are run by init when changing runlevels and are generally used to start and stop. For example turn on ssh service type the command:
# update-rc.d ssh defaults
OR
$ sudo update-rc.d ssh defaults
Again use update-rc.d command:
# update-rc.d SERVICE-NAME remove