Re: Drive failure rates (was Re: DO NOT BUY Western Digital "Green" Drives (also present in WD "Elements" external USB cases))

2011-09-05 Thread Andrew McGlashan

D G Teed wrote a MESSY HTML message that wasn't trimmed.:

http://static.googleusercontent.com/external_content/untrusted_dlcp/labs.google.com/en//papers/disk_failures.pdf


Your email was horribly formatted, so it was much easier to junk the 
content.


Now, another factor, the drive failure rates are probably way 
understated in the general populace because the cost of the drives are 
so low and the effort to destroy personal data (if still possible) and 
everything else that goes into RMA is just not worth the effort.


We are talking about commodity items these days.  In times gone past, 
replacing a faulty drive was more expensive and the RMA process was 
worth it, but today it is quite often not work the trouble on the 
cheaper range of drives -- hence failure rates would surely go heavily 
under reported.


--
Kind Regards
AndrewM

Andrew McGlashan
Broadband Solutions now including VoIP


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Drive failure rates (was Re: DO NOT BUY Western Digital "Green" Drives (also present in WD "Elements" external USB cases))

2011-09-05 Thread D G Teed
On Sun, Sep 4, 2011 at 8:41 PM,  wrote:
>
>  - Original Message -
> *From: *Brad Rogers 
> *To: *Debian Users ML 
> *Sent: *9/4/2011 6:26:48 PM
> *Subject: *Re: DO NOT BUY Western Digital "Green" Drives (also present in
> WD "Elements" external USB cases)
>
> On Sun, 04 Sep 2011 13:27:51 -0400
> Doug  wrote:
>
> Hello Doug,
>
> > It's been a few years since I retired, but I remember the IT guys
> > replacing a _lot_ of Western Digital drives. I guess the
>
> In the same vein, I remember lots of Seagate drives being replaced. For
> a while the company had a nickname of Seacrate. Possibly because that's
> what most of their gear was worth at the time; Crating up, and chucking
> in the sea.
>
> At various times, products from certain companies go through a bad
> time. Usually, it can be attributed to some factor or other. For
> example, one drive manufacturer's drives started failing prematurely
> because the wrong type of bearing oil had been used. Such issues often
> go unnoticed until quite large numbers of faulty products are in use.
> The offending company earns a bad reputation until the next company comes
> along and makes a cock-up and everyone forgets about the first one.
>
> WD, Seagate, and just about every other drive manufacturer has gone
> through these cycles. It's nothing new, and will continue for years to
> come.
>
> --
> Regards _
> / ) "The blindingly obvious is
> / _)rad never immediately apparent"
> The man in a tracksuit attacks me
> I Predict A Riot - Kaiser Chiefs
>
> The two most recent studies (one based on Google hardware and one from
> Carnegie-Mellon) provide two interesting insights:
>
> 1.  While there does not appear to be a strong correlation between failures
> and manufacturers there is a strong correlation between drive models from a
> manufacturer and failures.  The inference is that WD may not be
> failure-prone but some WD products are failure-prone.
>
> 2.  There is not a strong dependency between drive temperature and
> failures.
>
>
> This is now a different topic than the original one on green drives.

Here is a study by google on their drive failure rates.
This is from a few years ago, but I believe the correlations would hold true
today:

http://static.googleusercontent.com/external_content/untrusted_dlcp/labs.google.com/en//papers/disk_failures.pdf

The failure rate rises at the three year mark under higher temperatures.
 This is
consistent with how I understood the relationship between temperature and
electronics.  It doesn't kill it immediately, but stresses the components
and
shortens the lifespan.

For some reason, there is more failure in low temperatures and young drives.
I suspect there is another variable in there they have not isolated, such as
low humidity and static electricity, or vibration, etc. - something that
would
have been common to the drives operating in a colder data centre.

There is also this 2007 study, showing the failure rates are much higher
than the theoretical
number thrown out by drive manufacturers:

http://www.pcworld.com/article/129558/study_hard_drive_failure_rates_much_higher_than_makers_estimate.html

However it is based on consumer returns, not actual verified bad disks.
Some of the responses from manufacturers in that article seem to want
the blame offloaded to the customer.

A comment from 2010 following the article says that at the current low
prices for
drives, they are at a commodity level.  Essentially he is saying there is no
room
for quality to be built in with $60 hard drives, and you should stock drives
the way bakers stock bags of flour.

Personally, I've seen an overall increase in electronics failures straight
off the shelf.
Indications are that motherboard makers, flash memory makers, etc.,
do not test or burn in the newly manufactured equipment to pull out the
usual
small percentage of manufacturing flaws.  With cheap electronics, they can't
afford to QA the final product - it is cheaper for the customer to test it
for
them and RMA it.