$ sudo service mysql start
start: Unknown job: mysql

$ sudo service mysql restart
stop: Unknown job: mysql
start: Unknown job: mysql

# /etc/init/mysql.conf
....
start on
stop on starting rc RUNLEVEL=[016]

# /etc/init/mysql.conf.old
....
start on runlevel [2345]
stop on starting rc RUNLEVEL=[016]

sudo sh -c 'echo manual >> /etc/init/mysql.override'

sudo sh -c 'echo start on never >> /etc/init/mysql.conf'

start on runlevel [!0123456]