From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q74MhfbH087858 for ; Sat, 4 Aug 2012 17:43:41 -0500 Received: from ipmail06.adl2.internode.on.net (ipmail06.adl2.internode.on.net [150.101.137.129]) by cuda.sgi.com with ESMTP id 7X60LU8MCsUk8Rt9 for ; Sat, 04 Aug 2012 15:43:40 -0700 (PDT) Date: Sun, 5 Aug 2012 08:43:36 +1000 From: Dave Chinner Subject: Re: xfs_growfs / planned resize / performance impact Message-ID: <20120804224336.GS2877@dastard> References: <5017E426.2040709@profihost.ag> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5017E426.2040709@profihost.ag> 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 Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Stefan Priebe - Profihost AG Cc: "xfs@oss.sgi.com" On Tue, Jul 31, 2012 at 03:56:54PM +0200, Stefan Priebe - Profihost AG wrote: > Hello list, > > i'm planning to create a couple of VMs with just 30GB of space while > using xfs as the main filesystem. > > Now i alreay know that some of the VMs will grow up to 250GB while > resizing the block device and using xfs_growfs. Just use thin provisioning and make it 250GB to begin with. Thin provisioning mades filsystem grow/shrink pretty much redundant.... > Should i take care of that and format these disks with special parameters? > > I've discovered that a 500GB volume has agcount=4 and 64000 blocks > of internal log - while a 300GB volume resized to 500GB has agcount > 7 ad only 40960 blocks of internal log. I doubt you'll ever notice the difference. > Is it a problem if this grow will happen in small portions (30GB => > 50GB => 75GB => 100GB => ... 300GB)? Growing a filesystem by an order of magnitude is the limit of what I'd suggest is sane. Growing it by two orders of magnitude (espcially if you start with a 16 AG filesystem because of stripe alignment) is going to cause problems with the number of AGs and the subsequent freespace management scale issue.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs