RHEL7でCtrl+Alt+Deleteを無効にする

・Question
On RHEL7, /etc/init/control-alt-delete.override no more working to override key combination, how to disable the Ctrl-Alt-Del in RHEL7 ?

・Answer
If requirement is to disable the ctrl + Alt + delete key combination, one need to mask a service. This is like disabling a service,

Run the following command:

NOTE: systemd will recognize units symlinked to /dev/null and show them as masked. If one try to send key combination, this will fail with following similar error.