Re: Western Digital GreenPower drives and Linux

From: Tvrtko A. Ursulin
Date: Thu Apr 10 2008 - 03:47:47 EST


On Wednesday 09 April 2008 21:18:35 Tvrtko A. Ursulin wrote:
> I got one of them (WD5000AACS) recently and to my horror after less than
> three days of being power on this is what I saw:
>
> 9 Power_On_Hours 0x0032 100 100 000 Old_age Always - 66
> 193 Load_Cycle_Count 0x0032 197 197 000 Old_age Always - 10233
>
> At this rate the disk would reach it's design limit for load/unload cycles
> in around 80 days. Not good - so I implemented a lame workaround of keeping
> disk busy every couple of seconds - hopefully that won't kill it sooner
> that unloads would..
>
> I am also currently talking with first line of WD's tech support trying to
> get some data on how exactly those drives manage head unloading, but that
> may not lead anywhere useful.

I got back from WD's tech support and received a DOS utility which can control
this drive feature, apparently using vendor specific commands. With it head
unload timer can be disabled or set to a period between 100ms and 25.5s.

Of course I asked for more than a DOS utility, but the question really is how
was this feature intended to work with Windows for example, is there
something there which would prevent such rapid load/unload cycle growth, and
why isn't it documented somewhere?

I am kind off hoping that someone from WD is reading this list and will notice
this in case my effort with tech support fails.

Tvrtko
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/