If you're used to doing "reboot now" on a Linux VPS, don't do it here if you're running Ubuntu 13.04! It will lock you out and get you stuck - you'll need to mess about with the virtual console to get back in. I had a google and found this: http://ubuntuforums.org/showthread.php?t=2139160 It's a bug that Ubuntu are aware of, so basically, "reboot now" shouldn't be used with 13.04,