ILO virtual commands
Momentary press – this is like pressing the power button on your laptop/pc or server, with Windows 2000 and above (if I remember correctly), it should cleanly shut down the operating system
Press and hold – this is like pressing and holding the power button, it will turn off the computer completely and will not cleanly shut down the server
Cold boot of the system – this effectively powers off the server and restarts it.
Reset system – this is the ILO way of rebooting it without cleanly restarting the operating system, if your server has hung and wont respond, this might be the option you select.