From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 88BF07F4E for ; Sat, 21 Dec 2013 19:41:48 -0600 (CST) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay1.corp.sgi.com (Postfix) with ESMTP id 5F9058F8039 for ; Sat, 21 Dec 2013 17:41:45 -0800 (PST) Received: from greer.hardwarefreak.com (mo-65-41-216-221.sta.embarqhsd.net [65.41.216.221]) by cuda.sgi.com with ESMTP id dLPqulljWX5k39Ze for ; Sat, 21 Dec 2013 17:41:41 -0800 (PST) Message-ID: <52B64351.4040806@hardwarefreak.com> Date: Sat, 21 Dec 2013 19:41:37 -0600 From: Stan Hoeppner MIME-Version: 1.0 Subject: Re: md-RAID5/6 stripe_cache_size default value vs performance vs memory footprint References: <52B102FF.8040404@pzystorm.de> <52B2FE9E.50307@hardwarefreak.com> <52B41B67.9030308@pzystorm.de> <201312202343.47895.arekm@maven.pl> <52B57912.5080000@hardwarefreak.com> In-Reply-To: <52B57912.5080000@hardwarefreak.com> 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 Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: =?UTF-8?B?QXJrYWRpdXN6IE1pxZtraWV3aWN6?= Cc: linux-raid@vger.kernel.org, "xfs@oss.sgi.com" On 12/21/2013 5:18 AM, Stan Hoeppner wrote: ... > For example, I assisted a user with 5x Intel SSDs back in January and > his system required 4096, or 80MB of RAM for stripe cache, to reach > maximum write throughput of the devices. This yielded 600MB/s or 60% > greater throughput than 2048, or 40MB RAM for cache. In his case 60MB > more RAM than the default was well worth the increase as the machine was > an iSCSI target server with 8GB RAM. Correction here. I said above that 80MB was 60MB greater than the default for his 5 drives. This should have said 75MB greater than the default which is 1MB per member device, or 5MB for 5 drives. -- Stan _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs