Q. How do I reboot a UNIX system computer?
A. To reboot UNIX system type the following command at a shell prompt. To restart the operating system, enter:
shutdown -y -i6 -g120 “*** Rebooting Server kernel upgrade ****”
First, command will warn all users logged in of the impending loss of service. In this example message is “*** Rebooting Server kernel upgrade ****”. The -g120 is nothing but grace period, which allow the super user to change the number of seconds from the 60-second default. If you do not wish to provide warning and would like to reboot immediately, enter:
shutdown -y -i6 -g