On 4/12/06, Ted Byers <r.ted.byers@rogers.com> wrote:
>
> > ----- 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
there are reasons to go with raid 5 or other raids. where I work we
often do 14 drive raid 6 plus 1 hot swap on a 15 drive tray. However,
for 4 drive raid, I think 0+1 is the by far the best choice. For
three drive, I'd suggest two drive raid 1 plus hot swap.
> 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?
I would stay clear of cheaper NAS solutions (AoE, iscsi) unless you
really didn't care about performance. In my experience the better
SANs are a good way to go if you need flexibility or easy managment
(especially if you need to do things besides database) without losing
performance. A good SAN makes everything easy but boy do you pay for
it.
If you want most bang for the buck, I'd suggest either attached scsi
or sata (especially the latter). With sata, 24 raptors will get you
insane performance for a very reasonable price. Most of my apps are
cpu bound anyways.