From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756921Ab0EGQMF (ORCPT ); Fri, 7 May 2010 12:12:05 -0400 Received: from neskaya.eckenfels.net ([195.49.138.57]:63001 "EHLO neskaya.eckenfels.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755835Ab0EGQMD (ORCPT ); Fri, 7 May 2010 12:12:03 -0400 X-Greylist: delayed 2463 seconds by postgrey-1.27 at vger.kernel.org; Fri, 07 May 2010 12:12:03 EDT Date: Fri, 7 May 2010 17:28:31 +0200 (CEST) Message-Id: <201005071528.o47FSVas054141@neskaya.eckenfels.net> From: Bernd Eckenfels To: linux-kernel@vger.kernel.org Subject: Re: ext4 is faster with LVM than without, and other filesystem benchmarks In-Reply-To: <20100507142310.GF13143@lh.kyla.fi> X-Newsgroups: ka.lists.linux.kernel User-Agent: tin/1.8.3-20070201 ("Scotasay") (UNIX) (FreeBSD/7.2-PRERELEASE (i386)) X-SA-Exim-Connect-IP: 127.0.0.1 X-SA-Exim-Mail-From: ecki@neskaya.eckenfels.net X-SA-Exim-Scanned: No (on neskaya.eckenfels.net); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In article <20100507142310.GF13143@lh.kyla.fi> you wrote: > I think the most surprising result of the benchmarks is that ext4 > seems to be significantly faster under LVM than on the raw /dev/sdd1 > partition. Without LVM the variance in run times is much larger. Sounds like the syncs/barriers never reach the disk with LVM. What mount journal/sync options did you use? default? Is dmesg telling you that barriers have been turned off for the lvm case? IF yo uwant it fast and dirty try nobarrier,data=writeback :) Greetings Bernd