Commenting out the line with a # listed below in your /etc/inittab file will disable the possibility of using the Ctrl-Alt-Delete command to shutdown your computer. This is pretty important if you don't have the best physical security on the box. To do this, edit the inittab file vi /etc/inittab and change the line:

            ca::ctrlaltdel:/sbin/shutdown -t3 -r now
            

To read:

            #ca::ctrlaltdel:/sbin/shutdown -t3 -r now
            

Now, for the change to take effect type in the following at a prompt:

            [root@deep] /#/sbin/init q