From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q73DkFeL108636 for ; Fri, 3 Aug 2012 08:46:15 -0500 Received: from mail.sandeen.net (sandeen.net [63.231.237.45]) by cuda.sgi.com with ESMTP id BSXXqJ67PqTzrKgu for ; Fri, 03 Aug 2012 06:46:13 -0700 (PDT) Message-ID: <501BD625.9000505@sandeen.net> Date: Fri, 03 Aug 2012 08:46:13 -0500 From: Eric Sandeen MIME-Version: 1.0 Subject: Re: xfs_growfs / planned resize / performance impact References: <5017E426.2040709@profihost.ag> <501B4D7E.1000303@sandeen.net> <501B6B04.2090002@profihost.ag> In-Reply-To: <501B6B04.2090002@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 8/3/12 1:09 AM, Stefan Priebe - Profihost AG wrote: > Am 03.08.2012 06:03, schrieb Eric Sandeen: >> On 7/31/12 8:56 AM, 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. >>> >>> 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. >>> >>> Is it a problem if this grow will happen in small portions (30GB >>> => 50GB => 75GB => 100GB => ... 300GB)? >> >> This incremental part doesn't matter a bit. The first mkfs will >> choose the AG count & size according to defaults; further growth >> after this will add new (possibly partial) AGs of that pre-chosen >> size. > > OK thanks for your reply. But does this influence performance? Should > i perhaps start creating the 30GB with agcount 1 so that while > raising the disk i don't end up with such a high agcount value? Does > it make sense to create a bigger internal log from he beginning? You can't make a single-AG filesystem, for starters. I'd really suggest that you just do some testing, and see if your proposed mkfs/growth plan impacts your VM performance in any significant way. -Eric > Thanks > > Stefan > _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs