From owner-freebsd-performance@FreeBSD.ORG  Sat Sep 11 09:30:37 2004
Return-Path: <owner-freebsd-performance@FreeBSD.ORG>
Delivered-To: freebsd-performance@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 59E4C16A4CE
	for <freebsd-performance@freebsd.org>;
	Sat, 11 Sep 2004 09:30:37 +0000 (GMT)
Received: from outmx004.isp.belgacom.be (outmx004.isp.belgacom.be
	[195.238.2.101])
	by mx1.FreeBSD.org (Postfix) with ESMTP id B838F43D58
	for <freebsd-performance@freebsd.org>;
	Sat, 11 Sep 2004 09:30:36 +0000 (GMT)
	(envelope-from geert@lori.mine.nu)
Received: from outmx004.isp.belgacom.be (localhost [127.0.0.1])
	with ESMTP id i8B9UWL9018573
	for <freebsd-performance@freebsd.org>;
	Sat, 11 Sep 2004 11:30:32 +0200
	(envelope-from <geert@lori.mine.nu>)
Received: from lori.mine.nu (19-141.244.81.adsl.skynet.be [81.244.141.19])
	with ESMTP id i8B9UVHV018566;	Sat, 11 Sep 2004 11:30:31 +0200
	(envelope-from <geert@lori.mine.nu>)
Received: by lori.mine.nu (Postfix, from userid 1000)
	id 1AC76659; Sat, 11 Sep 2004 11:30:31 +0200 (CEST)
Date: Sat, 11 Sep 2004 11:30:30 +0200
From: Geert Hendrickx <geert.hendrickx@ua.ac.be>
To: Willem Jan Withagen <wjw@withagen.nl>
Message-ID: <20040911093030.GA40729@lori.mine.nu>
References: <20040831133551.GA86660@lori.mine.nu>
	<4134B312.8030309@pacific.net.sg> <1093958674.680.2.camel@book>
	<20040831183908.GA87694@lori.mine.nu> <4141AA6A.2070802@withagen.nl>
	<20040910160051.GA24152@lori.mine.nu> <41422463.9090303@withagen.nl>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <41422463.9090303@withagen.nl>
User-Agent: Mutt/1.4.2i
X-GPG-Key: http://lori.mine.nu/gnupgkey.asc
X-GPG-Key-ID: 1024D/766C1E92
X-Accept-Language: nl,en
cc: freebsd-performance@freebsd.org
cc: oceanare@pacific.net.sg
Subject: Re: spreading partitions over multiple drives
X-BeenThere: freebsd-performance@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Performance/tuning <freebsd-performance.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-performance>,
	<mailto:freebsd-performance-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-performance>
List-Post: <mailto:freebsd-performance@freebsd.org>
List-Help: <mailto:freebsd-performance-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-performance>,
	<mailto:freebsd-performance-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 11 Sep 2004 09:30:37 -0000

> Memory is cheap, I payed the other day something like < 100 Euro for 
> 512Mb. I chose to use more memory versus buying faster processors. Next 
> thing I would do is increase the number of spindels (aka disks), 
> especially on the boxes that have losts of access from different clients 
> for very different things.

Instead of working out optimal partition layouts across the drives, I
could also just use a Vinum RAID of course.  

I wouldn't opt for a RAID-0 configuration, as it seems too stupid to
lose the entire contents of *two* disks when *one* of them fails.  

How does a RAID-1 compare to having only one disk, performancewise?
When will Vinum use parallel reads?  When one process is reading big
chunks, or only when two or more processes are reading concurrently?  Or
is the Vinum RAID-1 algorithm not optimized for performance at all?  

Any thoughts/experiences on this?  

GH