From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 4FF0D7CA2 for ; Fri, 29 Jan 2016 16:26:13 -0600 (CST) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay3.corp.sgi.com (Postfix) with ESMTP id D7423AC002 for ; Fri, 29 Jan 2016 14:26:09 -0800 (PST) Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id 5nRN2Rb7TSRQKOdZ for ; Fri, 29 Jan 2016 14:26:07 -0800 (PST) Date: Sat, 30 Jan 2016 09:25:53 +1100 From: Dave Chinner Subject: Re: Random write result differences between RAID device and XFS Message-ID: <20160129222553.GK20456@dastard> References: <56AB44AF.8020807@purplehaze.ch> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <56AB44AF.8020807@purplehaze.ch> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Christian Affolter Cc: xfs@oss.sgi.com On Fri, Jan 29, 2016 at 11:53:35AM +0100, Christian Affolter wrote: > Hi everyone, > > I'm trying to understand the differences of some bandwidth and IOPs test > results I see while running a random-write full-stripe-width aligned fio > test (using libaio with direct IO) on a hardware RAID 6 raw device > versus on the same device with the XFS file system on top of it. > > On the raw device I get: > write: io=24828MB, bw=423132KB/s, iops=137, runt= 60085msec > > With XFS on top of it: > write: io=14658MB, bw=249407KB/s, iops=81, runt= 60182msec Now repeat with a file that is contiguously allocated before you start. And also perhaps with the "swalloc" mount option. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs