Do you know that if you push Ctrl-Alt-Delete on your linux will halt?
Now you know!
This is write on /etc/inittab file (inittab file describes which processes are started at bootup and during normal operation).
To disable Ctrl-Alt-Delete shutdown, open inittab file
|# vi /etc/inittab
Search the line like this
|ca:12345:ctrlaltdel:/sbin/shutdown -t3 -r now
Comment out the line with hash mark (#). Save the file end exit.
reboot the system to take effect or type command
|# init q