Details:

I use Mandrake 9.2 with a kernel I compiled with ACPI and APM support.
The kernel is 2.6.1. Patches for supermount has also been applied.

Question:

How to make use of the powerbutton on the cabinet to powerdown my linux system.

You don't I think. Just type halt or reboot as root into any command prompt.

Well I know the other ways to shutdown the conputer. I need to know about this. If it is possible in say, windoze then it "must" be possible in our Linux. A nifty feature for desktop users. Would not mind hibernating my system either. I am waiting for the SWAP "file" implementation of hibernation in Linux 2.6+.

Thanks for the interest.

If you have acpi enabled at boot (acpi=on kernel arguemnt) then all you have to do is get the acpi and acpid services running:

# chkconfig acpid on
# chkconfig acpi on
# service acpid start
# service acpi start

If you don't see any output when you start the acpid service then chances are acpid wasn't enabled at boot. Provided you have the suspend-scripts package then /etc/acpid/events/power should look something like this:

event=button/power (PWR.|PBTN)
action=/sbin/poweroff

So when you press the power button /sbin/poweroff is run. I haven't tried this with kernel 2.6.x but I have managed to shutdown my box by pressing the power button.

U were right hazza. I just had to enable the services and voila!
Thanks!:-)
Can u trap the reboot button and do a proper reboot with a high priority interrupt or something? It might help when the computer hangs hopelessly(although a lot less for other people. I fiddle around a lot!)