Remote Rebooting of Server
From Lunarpages Web Hosting Wiki
Q: How does the remote management of a dedicated server work if I want to reboot my server?
A: Unless the server is totally unresponsive you can reboot your server through WHM or in shell by typing reboot (enter) when at root. If the server is unresponsive and you are not able to use these methods send an email to firstname.lastname@example.org or call 714-521-8150.