OK this is just a copy of post I just sent in the Mandriva forums, hoping I get more feedback here:

...have had the issue for about two days now; been posting about it in the French section already (sorry for the double topic guys, but I need some feedback about that). So the issue is an audible and recurrent hdd click, like every 5 seconds sometimes. That does just happen under Linux, and not in Windows. I googled that and found that other users have experienced the same. It should be related to power management in Linux parking hdd heads again and again to save energy. You can read about it here:
http://translate.google.fr/translate?u= ... r&ie=UTF-8

also there (scroll til midpage)
http://translate.google.fr/translate?u= ... r&ie=UTF-8
the guy advises to do that, haven't tried it yet:

hdparm-B 254 / dev / sda


on my machine the issue disappears as soon as I remove everyting related to KDE power management in mandriva, or if I switch to Windows, so...not what I'd call solutions. Any tip on that one would be appreciated. I mean guys I'm not kidding, that's a serious issue that everyone might not have, but bad enough when it happens to be taken into account by the devs. It has happened to Ubuntu users, and Ubuntu devs are taking care of the issue...I mean they at least acknowledged it...

I'm adding: have had the issue in Mandriva 2009 upgraded to KDE 4.2. Rolled back to KDE 4.1 (new install actually), and the issue's still there.

(hardware is a laptop Acer 5735Z with Intel GMA 4500 chipset)

Which KDE Power Management systems are we talking about? As far as I am aware Powerdevil does not do anything related to the hard disk. Which power manager do you use under KDE 4.1.x?

PS: The command given to you will shutdown all Power Management for that hard drive, and it should work, although it will need to be executed as root.

bcooksley wrote:Which KDE Power Management systems are we talking about? As far as I am aware Powerdevil does not do anything related to the hard disk. Which power manager do you use under KDE 4.1.x?

PS: The command given to you will shutdown all Power Management for that hard drive, and it should work, although it will need to be executed as root.

OK I guess I got a little bit mixed up between what Kpowermanagement does, what laptop tools does, what comes from KDE and what does not...I've upgraded again to KDE 4.2 and I'm using the power management GUI triggered by the applet in the taskbar, that now contains more options than it use to in KDE 4.1. So this is KDE stuff obviously. And that's right, there's nothing in the GUI showing any interference with hard disk management, only CPU/Screen/Battery...
Now on the other side there's "laptop-tools" that doesn't appear to have anything to do with KDE, and that manages hard disks. In my last post I said that when I deactivated completely laptop tools and KPowermanagement the hard disk clicks disappeared and that was a mistake, they don't.
And finally adding the command "hdparm -B 254 /dev/sda" to the file "/etc/rc.d/rc.local " does get me rid of those hard disk clicks; but it does only work on AC mode apparently. As soon as I switch to battery mode, the clicks are there again. I now realize this is no KDE issue at all...
From what I've been told, the command "hdparm -B 254 /dev/sda" is supposed to override the bios; so the issue should come from the bios (?)..but it doesn't happen in Windows, so I suppose Windows just does things differently...
As to Linux, I've been advised to modify the "/etc/laptop-mode/laptop-mode.conf " file to get things fixed in both AC/battery mode, but it doesn't seem to work; I might have done something wrong when editing it; so at the moment I'm sticking to AC mode as long when I run Linux; funny, I never would have thought such an issue could exist. Anyway, that's all I can say about it now, and sorry if that in fact doesn't really belong to KDE forums

But while playing with the new KDE 4.2 powermanagement interface yesterday, I noticed a couple of small issues:
my laptop power button keeps shutting down the system, no way to make " it suspend to ram", even when the mode is selected (suspend to ram works from the applet button).
when modifying anything in the GUI, the "default" button is always grayed
hibernation ability seems to have completely disappeared, from the GUI at least (haven't tried the command line)

Powerdevil has multiple profiles, you may need to ensure the appropriate profile is activated.
Also, Powerdevil works best if there are no other Power managers, which could be another reason for the system shutting down.