From: Scott Marlowe <scott.marlowe@gmail.com>
To: Mario Weilguni <mweilguni@sime.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Experience with HP Smart Array P400 and SATA drives?
Date: Fri, 5 Dec 2008 16:00:53 -0700
Message-ID: <dcc563d10812051500h331ac82fp62142cf611b3a79d@mail.gmail.com> (raw)
In-Reply-To: <4934FE60.30702@sime.com>
References: <4934FE60.30702@sime.com>
On Tue, Dec 2, 2008 at 2:22 AM, Mario Weilguni <mweilguni@sime.com> wrote:
> Has anyone benchmarked this controller (PCIe/4x, 512 MB BBC)? We try to use
> it with 8x SATA 1TB drives in RAID-5 mode under Linux, and measure strange
> values. An individual drive is capable of delivering 91 MB/sec sequential
> read performance, and we get values ~102MB/sec out of a 8-drive RAID5, seems
> to be ridiculous slow. Write performance seems to be much better, ~300 MB
> /sec - seems ok to me.
>
> I guess I must be doing something wrong, I cannot believe that a 500 €
> controller is delivering such poor performance.
A few suggestions... Try to find the latest driver for your card, try
using the card as nothing but a caching controller and run your RAID
on software in linux (or whatever IS you're on). Test a 2 drive
RAID-0 to see what kind of performance increase you get. If you can't
dd a big file off of a RAID-0 at about 2x the rate of a single drive
then something IS wrong with it. Try RAID 10. Try RAID-1 sets on the
controller and RAID 0 over that in software.
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To: pgsql-performance@postgresql.org
Cc: scott.marlowe@gmail.com, mweilguni@sime.com
Subject: Re: Experience with HP Smart Array P400 and SATA drives?
In-Reply-To: <dcc563d10812051500h331ac82fp62142cf611b3a79d@mail.gmail.com>
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