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* Western Digital GreenPower drives and Linux
@ 2008-04-09 20:18 Tvrtko A. Ursulin
  2008-04-10  7:48 ` Tvrtko A. Ursulin
  2008-04-16 11:40 ` Helge Hafting
  0 siblings, 2 replies; 18+ messages in thread
From: Tvrtko A. Ursulin @ 2008-04-09 20:18 UTC (permalink / raw)
  To: linux-ide, linux-kernel


Hi all,

The subject may be a bit misleading since I haven't investigated the whole 
issue under other OS-es (nor do I plan to), but this is how the story goes..

Those fancy new WD GreenPower drives seem to be heavily suffering from the 
rapidly increasing head load/unload problem. And the bad thing is they don't 
respond to 'hdparm -B', which would mean (I think) their power management 
behaviour is solely up to their firmware.

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.

So in parallel I decided to ask here to see if someone knows something about 
this?

If it matters, I am running vanilla 2.6.24 on that box and sata_sil is driving 
that disk. Otherwise it is a pretty basic Ubuntu 7.10, a mix of ext3 and jfs 
filesystems, all mounted with noatime. More detailed information available on 
request.

Tvrtko





^ permalink raw reply	[flat|nested] 18+ messages in thread
* Re: Western Digital GreenPower drives and Linux
@ 2008-04-10 22:36 devzero
  2008-04-11 21:00 ` Tvrtko A. Ursulin
  0 siblings, 1 reply; 18+ messages in thread
From: devzero @ 2008-04-10 22:36 UTC (permalink / raw)
  To: lkml, pernegger, tvrtko; +Cc: linux-ide, linux-kernel

i also have such a drive (damn, if i knew that saving some Watts would hurt...) - and i measured ~100 load_cycle_count per hour, which is _way_ to much, imho.
if we trust the spec, the disk would be dead after ~1year.

it seems that "intellipark" is not that intelligent as it should be and a little bit too agressive.

from what i have found, the time for parking the heads is much below the linux kernel flush interval (which seems to be at 30secs),  so i think the best thing to do is tuning either dirty_expire_centisecs and dirty_writeback_centisecs  (defaults to 3000/500 on my system)  or tune the disk parking interval , so that the disks own interval is greater than the linux flush interval.

i also openend an SR at WD - will see if they will recommend that dos utility, too.

>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. 

doh - so that disk always is faster with parking it`s heads than linux default flush interval !?
btw - is that dos utility available for download somewhere?

regards
roland



List:       linux-kernel
Subject:    Re: Western Digital GreenPower drives and Linux
From:       "Tvrtko A. Ursulin" <tvrtko () ursulin ! net>
Date:       2008-04-10 7:48:08
Message-ID: 200804100848.08442.tvrtko () ursulin ! net
[Download message RAW]

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
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^ permalink raw reply	[flat|nested] 18+ messages in thread

end of thread, other threads:[~2008-04-16 19:45 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-04-09 20:18 Western Digital GreenPower drives and Linux Tvrtko A. Ursulin
2008-04-10  7:48 ` Tvrtko A. Ursulin
2008-04-10 12:44   ` Kasper Sandberg
2008-04-10 15:01     ` Christian Pernegger
2008-04-12 17:11       ` Jan Engelhardt
2008-04-13 15:41         ` Mark Lord
2008-04-16 11:40 ` Helge Hafting
2008-04-16 17:59   ` Christian Pernegger
2008-04-16 18:18     ` Mark Lord
2008-04-16 19:44     ` Tvrtko A. Ursulin
2008-04-16 19:46   ` Tvrtko A. Ursulin
  -- strict thread matches above, loose matches on Subject: below --
2008-04-10 22:36 devzero
2008-04-11 21:00 ` Tvrtko A. Ursulin
2008-04-12  3:19   ` Mike Snitzer
2008-04-12  7:11     ` Tvrtko A. Ursulin
2008-04-12 15:20       ` Mike Snitzer
2008-04-12 15:56         ` Mike Snitzer
2008-04-13  8:30           ` Niels

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