If you can't reboot your Dedicated Server via SSH, you can restart it from your hosting account. Restarting a Dedicated Server means a full power cycle, so be sure to save any unsaved files before you continue.

Go to your Client Area: https://my.tsohost.com/clientarea.php and follow these steps:

Services -> My Services -> click on the green "Active" button -> Login to Server ->

In the upper-right corner of the page click Server Actions > Power Cycle.

Click Request Power Cycle. The power cycle begins and may take a few minutes. When it's done the cycle is added to the History list for the server.