Use the status-all switch to list all services which are registered with the OS. The display will also indicate if the service is started during statup.
[ + ] – Services with this sign will start at OS boot.
[ - ] – Services with this sign do not start at OS boot.
service --status-all
Remove a service
Use the remove keyword with update-rc.d to remove the service start up command for an application. You will need to use the -f switch if the applications /etc/init.d start up file exists.
update-rc.d -f apache2 remove
Disable a service
update-rc.d postfix disable
Add a service
Adding a service to Ubuntu or Debian is done with the update-rc.d command. You can specify which runlevels to start and stop the new service or accept the defaults. The init.d file will be added to the relevent rc.d startup folders.
update-rc.d apache2 defaults