What do the commands shutdown -r and reboot do?
The shutdown and reboot commands have been designed to behave on a virtual level as close as possible to the same way they would on a dedicated UNIX server. Because you do not have access to the physical system to manually start up the system, you can not completely halt your VPS v2 (the -h option for shutdown is disabled), but you can restart all the services on your server. The shutdown command will attempt to cleanly halt and restart services on your VPS2, including running the /etc/rc.shutdown commands. Any processes that do not exit cleanly are then killed, and the init process is restarted (init will then read your rc files and start up other services). the reboot command is different from shutdown because it does not attempt a clean shutdown of your system. Instead, reboot simply kills all your running processes and then runs init (which will run the rc scripts).
