From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id EBB9C7F77 for ; Sat, 30 Mar 2013 21:04:55 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay2.corp.sgi.com (Postfix) with ESMTP id C8D6C304043 for ; Sat, 30 Mar 2013 19:04:52 -0700 (PDT) Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id zfni2cdKZZ4I47Yc for ; Sat, 30 Mar 2013 19:04:51 -0700 (PDT) Date: Sun, 31 Mar 2013 13:04:49 +1100 From: Dave Chinner Subject: Re: Help with XFS in VMs on VMFS Message-ID: <20130331020449.GM6369@dastard> References: <51549F09.1090109@hardwarefreak.com> <20130328214550.GA3771@pirx.askja.de> <5154E6AC.9020402@hardwarefreak.com> <20130329202735.GX22182@sgi.com> <51573924.2020304@hardwarefreak.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <51573924.2020304@hardwarefreak.com> 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: Stan Hoeppner Cc: Ben Myers , Jan Perci , xfs@oss.sgi.com On Sat, Mar 30, 2013 at 02:12:36PM -0500, Stan Hoeppner wrote: > On 3/29/2013 3:27 PM, Ben Myers wrote: > > Hi Jan, > > > > On Thu, Mar 28, 2013 at 11:30:01PM -0400, Jan Perci wrote: > >> Back to XFS, in this context, is there any benefit in tuning some > >> parameters to get better performance, or will it all just be overshadowed > >> by poor performance of the VMDKs that tuning isn't worthwhile? > > > > At least get your stripe unit and width correct. > > http://xfs.org/index.php/XFS_FAQ#Q:_How_to_calculate_the_correct_sunit.2Cswidth_values_for_optimal_performance > > Is this really a good idea given that XFS sits atop a virtual disk which > consists of multiple concatenated 2TB sparse files sitting on the VMFS > filesystem, which, IIRC, has a 1MB sector size? Thus can one rely on > XFS being able to properly align to the physical RAID stripe, even if > the math is done 'properly' (if that's even possible here)? No, because VMFS doesn't do any specific alignment to the underlying storage geometry. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs