We have performed an unscheduled reboot of the server to correct an internal problem with the Lightweight Virtual Environment (LVE) system.The LVE helps to limit individual users on the server to not use an excessive amount of resources (CPU, RAM, processes) and thereby slowing down other websites on the server. Problems like the one we experienced today are rare.
Update 18:03 GMT
We are applying a patch for the LVE system together with a Linux kernel upgrade. The update requires another reboot. We apologise for any inconvenience.