Re: Why?

From: Howard J. Rogers <hjr_at_dizwell.com>
Date: Tue, 29 Jun 2004 06:23:29 +1000
Message-ID: <40e07e26$0$25463$afc38c87@news.optusnet.com.au>

"Michael Austin" <maustin_at_firstdbasource.com> wrote in message news:ZV_Dc.4564$145.4190_at_newssvr23.news.prodigy.com...
> Hans Forbrich wrote:
> > Alexander Skwar wrote:
> >
> >
> >>>No database should run RAID5.
> >>
> >>Why?
> >
> >
> > See http://www.baarf.com/ for a genreal discussion
> >
> > /Hans
>
>
> Do you know why they call if BAARF? Because after you read it you
> will... barf. I have still not found anyone who has been able to -
> through os-level stats - quantify this supposed "write" penalty on real
> computers using SAN technology and latest storage technology. If you
> are talking about that (AMD/INTEL) server with n-internal IDE's then
> maybe. You can show all the math "proving" a point, but as you and I
> well know, what is theoretical and what is real are quite different from
> "server" to "server". 90% of all database applications out there would
> never see using RAID5 as a problem or bottleneck.
>
> Michael Austin.

In a world where I would be forced to make a choice between the advice of Cary Millsap or Michael Austin, you will forgive me, I'm sure, if I elect to go the Cary Millsap route. Read his paper, please. There's more to it than the write penalty... I mentioned it only in passing because of the original poster's unqualified adoption of RAID5 as the storage mechanism of choice.

Regards
HJR Received on Mon Jun 28 2004 - 15:23:29 CDT