How to disable ctrl-alt-delete?

Hi,

We normally protect our installs from the combination of a large windows support organization, hp ILO and ctrl-alt-delete.

What is the correct way of doing this on the 3.0 hypervisor? I tried the following.

Disabled ctrl-alt-delete in /etc/init/control-alt-delete.conf

persist /etc/init/control-alt-delete.conf

If I do a init q, it works. Ctrl alt delete is disabled. But after reboot, ctrl-alt-delete "works" as a reboot again.

Any advice on the correct way of doing this would be appreciated.

Thnaks, Brian