service to start on boot doesn't work with update-rc.d command

I have installed redis server on my Ubuntu based server, so I can start/stop/restart redis server. The redis_server.sh is already in the /etc/init.d. Now I want to make redis start on boot. I learned from a website that by working with the update_rc.d command, I can add / remove the service on boot. I tried the update-rc.d to add startup on boot, which doesn't work: root@ip-172-31-4-108:/etc/init.d# update-rc.d redis-server defaults //System start/stop links for /etc/init.d/redis-server already exist. In addition, there are some services I don't want to startup on boot, so I tried: root@ip-172-31-4-108:/etc/init.d# update-rc.d reids_6379 remove Removing any system startup links for /etc/init.d/reids_6379 ... But when rebooting next time, I still see that service running on boot.