From mboxrd@z Thu Jan 1 00:00:00 1970 From: Luca Berra Subject: Re: MD RAID1 performance very different from non-RAID partition Date: Tue, 18 Sep 2007 15:44:38 +0200 Message-ID: <20070918134438.GA1522@percy.comedia.it> References: <46EB6D67.1000802@quo.to> <20070915070914.GA21515@teal.hq.k1024.org> <46EC2043.5010006@quo.to> <878x765kmy.fsf@informatik.uni-tuebingen.de> <46EEA413.8090706@quo.to> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <46EEA413.8090706@quo.to> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Mon, Sep 17, 2007 at 10:58:11AM -0500, Jordan Russell wrote: >Goswin von Brederlow wrote: >> Jordan Russell writes: >>> It's an ext3 partition, so I guess that doesn't apply? >>> >>> I tried remounting /dev/sda2 with the "barrier=0" option (which I assume >>> disables barriers, looking at the source), though, just to see if it >>> would make any difference, but it didn't; the database build still took >>> 31 minutes. >> >> Compare the read ahead settings. > >I'm not sure what you mean. There's a per-mount read ahead setting? > per device compare blockdev --getra /dev/sda2 and blockdev --getra /dev/md0 L. -- Luca Berra -- bluca@comedia.it Communication Media & Services S.r.l. /"\ \ / ASCII RIBBON CAMPAIGN X AGAINST HTML MAIL / \