Re: Hardware related question: 3ware 9500S

> ----- Original Message -----
> From: "Merlin Moncure" <mmoncure@gmail.com>
> To: "Janning Vygen" <vygen@gmx.de>
> Cc: <pgsql-general@postgresql.org>
> Sent: Wednesday, April 12, 2006 12:31 PM
> Subject: Re: [GENERAL] Hardware related question: 3ware 9500S
> [snip]

> > - I want to know if 3ware 9500 S is recommended or if its one of those
> > controllers which sucks.
>
> escalade is a fairly full featured raid controller for the price.
> consider it the ford taurus of raid controllers, it's functional and
> practical but not sexy.  Their S line is not native sata but operates
> over a pata->sata bridge.  Stay away from raid 5.
>
Hi Merlin

Why?  What's wrong with raid 5? I could well be wrong (given how little
attention I have paid to hardware over the past few years because of a focus
on developing software), but I was under the impression that of the raid
options available, raid 5 with hot swappable drives provided good data
protection and performance at a reasonably low cost.  Is the problem with
the concept of raid 5, or the common implementations?

Do you have a recommendation regarding whether the raid array is built into
the server running the RDBMS (in our case PostgreSQL), or located in a
network appliance dedicated to storing the data managed by the RDBMS?  If
you were asked to design a subnet that provides the best possible
performance and protection of the data, but without gold-plating anything,
what would you do?  How much redundancy would you build in, and at what
granularity?

Ted