How to Reboot your cPanel/whm in ssh
If you happen to mess up your ssh configuration some how you can reset the ssh config from Cpanel then restart your machine via ssh by using following command
/etc/init.d/cpanel restart
Enjoy!!!
Or
If you cannot reboot your server manually, you can restart it by requesting a power cycle.
1) Log in to your Account Manager ( cpanel/whm ).
2) Click Servers.
3) Next to the server you want to use, click Manage.
4) Click Power.
5) Click Restart.