From owner-freebsd-hackers@FreeBSD.ORG  Thu May 22 09:18:51 2003
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 032D137B401
	for <hackers@freebsd.org>; Thu, 22 May 2003 09:18:51 -0700 (PDT)
Received: from testmail.wolves.k12.mo.us (testmail.wolves.k12.mo.us
	[207.160.214.10])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 3DAFB43FA3
	for <hackers@freebsd.org>; Thu, 22 May 2003 09:18:50 -0700 (PDT)
	(envelope-from cdillon@wolves.k12.mo.us)
Received: by testmail.wolves.k12.mo.us (Postfix, from userid 1001)
	id 0CFFDCD1D; Thu, 22 May 2003 11:18:49 -0500 (CDT)
Received: from localhost (localhost [127.0.0.1])
	by testmail.wolves.k12.mo.us (Postfix) with ESMTP
	id 08164CD1C; Thu, 22 May 2003 11:18:49 -0500 (CDT)
Date: Thu, 22 May 2003 11:18:49 -0500 (CDT)
From: Chris Dillon <cdillon@wolves.k12.mo.us>
To: Jaye Mathisen <mrcpu@internetcds.com>
In-Reply-To: <20030522040643.GS75453@backmaster.cdsnet.net>
Message-ID: <20030522111408.G48288@duey.wolves.k12.mo.us>
References: <20030522040643.GS75453@backmaster.cdsnet.net>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
cc: hackers@freebsd.org
Subject: Re: Abysmal mly Extreme RAID performance in 5.0-p7?
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 22 May 2003 16:18:51 -0000

On Wed, 21 May 2003, Jaye Mathisen wrote:

> 206438400 bytes transferred in 27.405360 secs (7532775 bytes/sec)

What were the exact dd options you used for this?  If you didn't
specify a block size, the default block size of 512 bytes is used, and
you will get dismal performance figures no matter what kind of
hardware you have.  Increase the block size to at _least_ 64KB.  I
believe 128KB is the maximum block size FreeBSD will use, so testing
with block sizes above that won't matter much.

-- 
 Chris Dillon - cdillon(at)wolves.k12.mo.us
 FreeBSD: The fastest and most stable server OS on the planet
 - Available for IA32 (Intel x86) and Alpha architectures
 - IA64, PowerPC, UltraSPARC, ARM, and S/390 under development
 - http://www.freebsd.org

No trees were harmed in the composition of this message, although some
electrons were mildly inconvenienced.