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 1F8347CA3 for ; Thu, 14 Jul 2016 18:40:36 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay3.corp.sgi.com (Postfix) with ESMTP id 9AE37AC002 for ; Thu, 14 Jul 2016 16:40:35 -0700 (PDT) Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net [150.101.137.143]) by cuda.sgi.com with ESMTP id fgmjUS0gX8lIncGj for ; Thu, 14 Jul 2016 16:40:33 -0700 (PDT) Date: Fri, 15 Jul 2016 09:40:11 +1000 From: Dave Chinner Subject: Re: mkfs.xfs -d su=XXX,sw=YYY and future volume resize Message-ID: <20160714234011.GU1922@dastard> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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: Marcin Sura Cc: xfs@oss.sgi.com On Thu, Jul 14, 2016 at 10:19:02PM +0200, Marcin Sura wrote: > Hi, > > When I create filesystem I can specify su and sw paramteres which match > underlying storage device. > So for example, If I have raid 6 volume made of 6 + 2 disks with stripe > size of 256k I create xfs with: > > mkfs.xfs -d su=256k,sw=6 > > But what if I will extend original volume by 2 disks. sw will 8. Will be > there a performance panelty compared to filesystem created from scratch > with correct sw parameter? That depends on your workload more than anything. If the workload benefits from correct stripe alignment of your data and IO, then it will definitely perform worse if you change the stripe width so that allocation is no longer able to align correctly to the physical geometry of the storage. -Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs