Re: Bad iostat numbers

http://en.wikipedia.org/wiki/RAID_controller

Alex

On 12/4/06, Michael Stone <mstone+postgres(at)mathom(dot)us> wrote:
>
> On Mon, Dec 04, 2006 at 12:37:29PM -0500, Alex Turner wrote:
> >This discussion I think is important, as I think it would be useful for
> this
> >list to have a list of RAID cards that _do_ work well under Linux/BSD for
> >people as recommended hardware for Postgresql. So far, all I can
> recommend
> >is what I've found to be good, which is 3ware 9500 series cards with 10k
> >SATA drives. Throughput was great until you reached higher levels of
> RAID
> >10 (the bonnie++ mark I posted showed write speed is a bit slow). But
> that
> >doesn't solve the problem for SCSI. What cards in the SCSI arena solve
> the
> >problem optimally? Why should we settle for sub-optimal performance in
> SCSI
> >when there are a number of almost optimally performing cards in the SATA
> >world (Areca, 3Ware/AMCC, LSI).
>
> Well, one factor is to be more precise about what you're looking for; a
> HBA != RAID controller, and you may be comparing apples and oranges. (If
> you have an external array with an onboard controller you probably want
> a simple HBA rather than a RAID controller.)
>
> Mike Stone
>
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