From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261946AbTJIIzx (ORCPT ); Thu, 9 Oct 2003 04:55:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261947AbTJIIzx (ORCPT ); Thu, 9 Oct 2003 04:55:53 -0400 Received: from c-36a870d5.037-69-73746f23.cust.bredbandsbolaget.se ([213.112.168.54]:57473 "EHLO ford.pronto.tv") by vger.kernel.org with ESMTP id S261946AbTJIIzv (ORCPT ); Thu, 9 Oct 2003 04:55:51 -0400 To: Andre Tomt Cc: linux-kernel@vger.kernel.org Subject: Re: Software RAID5 with 2.6.0-test References: <1065655452.13572.50.camel@torrey.et.myrio.com> <1065660704.848.10.camel@slurv> From: mru@users.sourceforge.net (=?iso-8859-1?q?M=E5ns_Rullg=E5rd?=) Date: Thu, 09 Oct 2003 10:55:45 +0200 In-Reply-To: <1065660704.848.10.camel@slurv> (Andre Tomt's message of "Thu, 09 Oct 2003 02:51:44 +0200") Message-ID: User-Agent: Gnus/5.1002 (Gnus v5.10.2) XEmacs/21.4 (Rational FORTRAN, linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andre Tomt writes: >> When I tried it, I was running 2.6.0-test4. The RAID5 was 4 120 GB >> Seagate disks on a Highpoint controller. > > > >> The other thing that I don't like, is the performance of the RAID >> array. The disks individually give ~40 MB/s read speed, but the array >> only measures 25 MB/s. I was of the impression, that RAID5 would give >> read speeds at least equal to the underlying disks. Is this >> incorrect? > > Was this a 4 port or 2 port HPT controller? Keep in mind, two disks on > the same IDE channel severely degrades performance, *especially* with > RAID. It's a four port SATA controller. I'd never even think about placing two disks on the same cable. -- Måns Rullgård mru@users.sf.net