RE: upgrade advice

[Redeeman <redeeman@metanurb.dk>]

On Wed, 2008-12-17 at 08:28 -0600, David Lethe wrote:
> > -----Original Message-----
> > From: linux-raid-owner@vger.kernel.org [mailto:linux-raid-
> > owner@vger.kernel.org] On Behalf Of Jon Nelson
> > Sent: Wednesday, December 17, 2008 7:27 AM
> > To: Redeeman
> > Cc: Justin Piszcz; linux-raid@vger.kernel.org
> > Subject: Re: upgrade advice
> > 
> > > What sort of volume of disks are you using, and what loads? (24/7
> > with
> > > high load?)
> > 
> > It's a home server. It's up 24/7. Load probably 80% of the time is
> > low, the rest of the time it's bursty.
> > 
> > --
> > Jon
> > --
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> 
> Read the specs on the disks.  Most consumer class drives are rated for
> only 2400 hours annual duty cycle ... so I guess you turn the computer
> off in April? :)
> 
> Other differences include number of ECC correction bits, so you will
> absolutely get more grown bad blocks with cheap drives.
> 
> Consider also how many people complain about botched rebuilds due to
> multiple drive failures on rebuilds and bad blocks on surviving disks.
> I can't remember anybody who bought enterprise class disks asking for
> such help recently, it always seems to be people who buy consumer
> drives.   No wonder several fail within days of each other, they all
> have same model, I/O load, and generally same manufacturing batch.

Did you ever split open the consumer and "enterprise" versions of the
drives and observe?

While i do believe they do some more testing/quality control on the
enterprise disks, they are almost all identical excepting firmware.. so
to be fair, i'd say the mistake is not properly stress testing the
disks, and for instance just buying a huge batch of disks and putting to
use..

> 
> If you are hell-bent on getting cheap drives, then at least factor in
> cost of an additional drive so you can implement RAID6, and automate a
> daemon to check/repair consistency often.
> 
> Life is short.  Spend the extra money and get disks designed to run in
> servers, not PCs. Unless, of course, you have a rather large autochanger
> and love to use it.
> 
> 
> David
>  
> 
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