From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 8E2C57F52 for ; Mon, 4 Feb 2013 03:11:13 -0600 (CST) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay2.corp.sgi.com (Postfix) with ESMTP id 79DE4304053 for ; Mon, 4 Feb 2013 01:11:13 -0800 (PST) Received: from Ishtar.sc.tlinx.org (ishtar.tlinx.org [173.164.175.65]) by cuda.sgi.com with ESMTP id YJyR0bZ39Bj3uvjQ (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Mon, 04 Feb 2013 01:11:12 -0800 (PST) Message-ID: <510F7B2D.908@tlinx.org> Date: Mon, 04 Feb 2013 01:11:09 -0800 From: Linda Walsh MIME-Version: 1.0 Subject: Re: Looking for Linux XFS file system performance tuning tips for LSI 9271-8i + 8 SSD's RAID0 References: In-Reply-To: List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: rkj@softhome.net Cc: xfs-oss rkj@softhome.net wrote: > > I am working with hardware RAID0 using LSI 9271-8i + 8 SSD's... >... With Direct IO, the sequential writes are around > 3.5 GB/s but I noticed a drop-off in sequential reads for smaller record > sizes. ---- 1) Are you using the realtime partitions? 2) are you using an empty file space with max log size 3) what are you using to do write's with, "dd"? 4) have you tried pre-allocating the space, running xfs_fsr on the file, to get it to 1 extent in size, then run dd with the conv=nocreat,notrunc option? Those are some things to try for maximums. I notice ~30% hit if I go through the linux buffer system as well. Have you tried different write sizes? i.e. 32M, 64M, 128 256... i.e. I notice optimal sizes after which things fall off... do you run 'time' on "dd" as well and see how much cpu it is using? If you use bash, I find setting TIMEFORMAT to: "%2Rsec %2Uusr %2Ssys (%P%% cpu)" to be a useful format (1 line, and shows cpu % usage)... just some random thoughts... _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs