The standard start/stop scripts are located in /etc/init.d or for older linux versions /etc/rc.d/init.d.
Stop MySQL: /etc/init.d/mysql stop
Start MySQL: /etc/init.d/mysql start
If you run cPanel there is a restart script located at /scripts/restartsrv.
To restart MySQL run /scripts/restartsrv mysql
You can skip to the end and leave a response. Pinging is currently not allowed.