Date: Mon, 04 Dec 2006 12:43:22 -0500
From: Michael Stone <mstone+postgres@mathom.us>
Subject: Re: Bad iostat numbers
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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