Spin down HDD after disk sync or before power off

[Octavian Covalschi]

Hi everyone.

I'm looking a way to spin down HDD just right before power off. Why?

Because currently when I call "shutdown -p now", HDD is powered off at it's
full speed (7200.4) and as a result
I hear a noise of stopping/spinning down of HDD, and _this_ concerns me as
I'm afraid it can damage HDD.

So basically I want to spin down hdd/put into sleep mode before system is
powered off.

I've tried to use rc.shutdown, but the sync of disks "wakes" HDD again...

While searching for a solution, I noticed that reboot command/app _does_
spin down hdd right before it resets
system power, I can hear how HDD is powered on after that... but halt (which
is used by shutdown) doesn't do that...

2nd thing is I cannot find "halt.c" file, i wanted to take a look how it
does it... although I'm up to date it's not not in
/usr/src/sbin

Thank you in advance