[Ukfreebsd] "green" HDDs

Adrian Wontroba aw1 at stade.co.uk
Tue Jan 11 02:53:35 GMT 2011

On Mon, Jan 10, 2011 at 11:08:54PM +0000, Tim Borgeaud wrote:
> Bruce Cran wrote:
> >On Sun, 9 Jan 2011 17:09:51 +0000
> >dgmm <freebsd01 at dgmm.net> wrote:
> >
> >>Has anyone used these drives and have some observations on their use?
> >
> >I've used both the WD EARS and Samsung F3 series. By default the WD
> >drives will spin down after 8 seconds which make them useless for RAID
> >but that can be disabled using a Windows utility, wdidle3.exe. Even
> >then the random access performance is very poor.
> >
> I'm not certain about the WD EARS drives, but I suspect that the power 
> saving features are similar to other Western Digital drives.
> I have a couple of Western Digital 2.5" drives, they don't spin down every 
> 8 seconds, but they do park the heads after 8 seconds of inactivity.
> The wdidle3.exe tool which can change this timeout is, unfortunately, not 
> approved on recent drives. It apparently does a bit more than a simple ATA 
> command, it adjusts some software/firmware in the drive and was created 
> for older drives. It can be found, but as far as I know, it is no longer 
> available on the WD web site.
> However, I have used the ataidle utility to turn off the power management 
> features on my drives and prevent the head parking (note that I think that 
> ataidle doesn't work when ahci is used). The WD drives I have need the 
> power management setting to be changed whenever power is cycled.

My main home server has these 1.5 TB "green" WDC drives in it:
ada1: <WDC WD15EADS-00S2B0 04.05G04> ATA-8 SATA 2.x device
ada2: <WDC WD15EADS-00S2B0 04.05G04> ATA-8 SATA 2.x device
ada3: <WDC WD15EADS-00S2B0 04.05G04> ATA-8 SATA 2.x device
ada4: <WDC WD15EADS-65P8B1 01.00A01> ATA-8 SATA 2.x device
ada5: <WDC WD15EADS-00S2B0 04.05G04> ATA-8 SATA 2.x device
ada6: <WDC WD15EADS-00S2B0 04.05G04> ATA-8 SATA 2.x device

The oddball is a replacement for one of the original which failed (and
is still awaiting my running WD diagnostics on it so that I can return


Load cycle count - had climbed to over half the lifetime rating for the
drives e.g.
193 Load_Cycle_Count        0x0032   134   134   000    Old_age Always       -       200006
before I cottoned on to the problem and started running a script which
accesses every drive every 5 seconds.

I've twice had a drive drop out of the array due to error recovery
taking too long.

The next time I build a server from scratch I'll use server grade disks.

Adrian Wontroba
An alcoholic is a person who drinks more than his own physician.

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