By default, the /etc/inittab specifies that your system will reboot on pressing the Ctrl–Alt–Del key combination used at the console. To completely disable this feature, comment out the following line in /etc/inittab file (you will need admin privileges for this) by putting a hash mark (#) in front of itand save the file:
ca::ctrlaltdel:/sbin/shutdown -t3 -r now
You may also want some non-root users to be still able to shutdown the system using Ctrl–Alt–Del key combination, and for this provisions are available. Do the following:
- Add the
-aoption to the/etc/inittabline shown above, so that it reads:ca::ctrlaltdel:/sbin/shutdown -a -t3 -r now - Create a file named
shutdown.allowin/etc. Theshutdown.allowfile should list the usernames of any users who are allowed to shutdown the system using Ctrl–Alt–Del , as shown beloW:
#shutdown.allow fileuser1user2user3....userN
the -a switch in the above modified line only tells the shutdown script to look for a shutdown.allow file.