Re: RAID 5 and postgresql

On Sat, 2006-01-21 at 07:09, Sander Steffann wrote:
> Hi,
>
> > I would suppliment this with just saying that your controller card is
> > your performance,
> > the only cards I've seen score well on linux, and people have
> > expressed on this list for SCSI are the LSI card, for SATA, LSI, 3ware
> > (now AMCC) and Areca claim good linux support and seem to work well.
> > Steer full clear of Adaptec, Dell and Compaq controllers, and their
> > linux support is abysmal, and the performance reflects that,
> > particularly in RAID 5.
>
> Dell has used (and rebranded) Adaptec and LSI controllers for their PERC
> series, and I agree that the Adaptec controllers perform badly. As far as I
> know the LSI based controllers are quite good (and some come with 256MB
> battery backed cache, which is nice :-)

Last place I worked we used Dell rackmounts (2600 series mostly) and
they came, by default with the Adaptec based controllers. Those were
horrific, locking up under load, really poor performance, etc...

The LSIs, as you mentioned, were much better. We had exactly one Dell
2600 with the LSI (hmmm. Bet you can't guess who specced that machine
out, eh? hehe) with 256 Meg BBCache. While it never locked up or hung,
it's I/O was noticeable slower than the machine it replaced, which also
had an LSI RAID controller with BBCache, bascially, the same chipset.

I'm not sure if it's Dell's BIOS on the mobos, or something with the LSI
cards, but the performance was substandard.

So if you're working somewhere that you simply have to use Dell (not
uncommon), at least make sure you get the LSI based RAID controller.