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 q75CYv5X206395 for ; Sun, 5 Aug 2012 07:34:57 -0500 Received: from greer.hardwarefreak.com (mo-65-41-216-221.sta.embarqhsd.net [65.41.216.221]) by cuda.sgi.com with ESMTP id JKaerDgDgFqZmKXC for ; Sun, 05 Aug 2012 05:34:56 -0700 (PDT) Message-ID: <501E6872.6000503@hardwarefreak.com> Date: Sun, 05 Aug 2012 07:34:58 -0500 From: Stan Hoeppner 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> (sfid-20120803_140801_426027_0A33D973) <201208051303.09337.Martin@lichtvoll.de> In-Reply-To: <201208051303.09337.Martin@lichtvoll.de> Reply-To: stan@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 Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Martin Steigerwald Cc: Stefan Priebe - Profihost AG , Eric Sandeen , xfs@oss.sgi.com On 8/5/2012 6:03 AM, Martin Steigerwald wrote: > Well the default was 16 AGs for volumes < 2 TiB AFAIR. And it has been > reduced to 4 for as I remember exactly performance reasons. Too many AGs > on a single device can incur too much parallelity. Thats at least is what > I have understood back then. For striped md/RAID or LVM volumes mkfs.xfs will create 16 AGs by default because it reads the configuration and finds a striped volume. The theory here is that more AGs offers better performance in the average case on a striped volume. With hardware RAID or a single drive, or any storage configuration for which mkfs.xfs is unable to query the parameters, mkfs.xfs creates 4 AGs by default. The 4 AG default has been with us for a very long time. It was never reduced. -- Stan _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs