basically you're screwed. System doesn't boot up properly (at least ssh is not starting), and basically the only way to fix it is to go to datacentre, plug keyboard in and see what's going on. You can use KVM as well, but not many hosts offer it (none of those "hosting for 3$/month. warez allowed!" advertised at KWWHunction do ). Some hosts let you use netboot option, where you boot using different kernel than the one you have installed on your server....