From: Michael Stone <mstone+postgres@mathom.us>
To: pgsql-performance@postgresql.org
Subject: Re: Bad iostat numbers
Date: Tue, 05 Dec 2006 07:15:09 -0500
Message-ID: <20061205121507.GZ1622@mathom.us> (raw)
In-Reply-To: <33c6269f0612042221x5820e98bl96f8d0dc4a87bd3f@mail.gmail.com>
References: <PEEPKDFEHHEMKBBFPOOKKEHCDKAA.carlos.reimer@opendb.com.br>
<Pine.GSO.4.64.0612032336250.19679@westnet.com>
<33c6269f0612032317t9f0bc77n3ff791a5cd88fc80@mail.gmail.com>
<Pine.GSO.4.64.0612041946120.9323@westnet.com>
<33c6269f0612042221x5820e98bl96f8d0dc4a87bd3f@mail.gmail.com>
On Tue, Dec 05, 2006 at 01:21:38AM -0500, Alex Turner wrote:
>My other and most important point is that I can't find any solid
>recommendations for a SCSI card that can perform optimally in Linux or
>*BSD. Off by a factor of 3x is pretty sad IMHO. (and yes, we know the
>Adaptec cards suck worse, that doesn't bring us to a _good_ card).
This gets back to my point about terminology. As a SCSI HBA the Adaptec
is decent: I can sustain about 300MB/s off a single channel of the
39320A using an external RAID controller. As a RAID controller I can't
even imagine using the Adaptec; I'm fairly certain they put that
"functionality" on there just so they could charge more for the card. It
may be that there's not much market for on-board SCSI RAID controllers;
between SATA on the low end and SAS & FC on the high end, there isn't a
whole lotta space left for SCSI. I definitely don't think much
R&D is going into SCSI controllers any more, compared to other solutions
like SATA or SAS RAID (the 39320 hasn't change in at least 3 years,
IIRC). Anyway, since the Adaptec part is a decent SCSI controller and a
lousy RAID controller, have you tried just using software RAID?
Mike Stone
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To: pgsql-performance@postgresql.org
Cc: mstone+postgres@mathom.us
Subject: Re: Bad iostat numbers
In-Reply-To: <20061205121507.GZ1622@mathom.us>
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