From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe - Profihost AG Subject: Re: poor OSD performance using kernel 3.4 Date: Wed, 30 May 2012 08:33:11 +0200 Message-ID: <4FC5BF27.5060704@profihost.ag> References: <4FBE415E.8030702@profihost.ag> <4FC54CDB.1000506@inktank.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Return-path: Received: from mail.profihost.ag ([85.158.179.208]:52936 "EHLO mail.profihost.ag" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752132Ab2E3GdI (ORCPT ); Wed, 30 May 2012 02:33:08 -0400 In-Reply-To: <4FC54CDB.1000506@inktank.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Mark Nelson Cc: "ceph-devel@vger.kernel.org" > > I setup some tests today to try to replicate your findings (and also > check results against some previous ones I've done). I don't think I'm > seeing exactly the same results as you, but I definitely see xfs > performing worse in this specific test than btrfs. I've included the > results here. > > Full results are available here: > http://nhm.ceph.com/results/mailinglist-tests/ But these tests shows exactly he same bad behaviour i'm seeing. Instead of having a constant sequential write ratio you've heavily jumping values. Are you able to test with XFS and 3.0.32? You'll then probably see an absolutely constant write ratio. Greets, Stefan