From owner-freebsd-performance@FreeBSD.ORG Tue Sep 28 01:35:07 2010 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CA031106566B for ; Tue, 28 Sep 2010 01:35:07 +0000 (UTC) (envelope-from ssanders@softhammer.net) Received: from oproxy3-pub.bluehost.com (oproxy3-pub.bluehost.com [69.89.21.8]) by mx1.freebsd.org (Postfix) with SMTP id 9B04F8FC17 for ; Tue, 28 Sep 2010 01:35:07 +0000 (UTC) Received: (qmail 28703 invoked by uid 0); 28 Sep 2010 01:08:27 -0000 Received: from unknown (HELO host358.hostmonster.com) (66.147.240.158) by oproxy3.bluehost.com with SMTP; 28 Sep 2010 01:08:27 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=softhammer.net; h=Received:Message-ID:Date:From:User-Agent:MIME-Version:To:Subject:Content-Type:Content-Transfer-Encoding:X-Identified-User; b=X8corEn85EbWw22fZG5mQrYDAK+1tL8q6s1mQSctKk3C9j0PBRprkDSChIMzILA3qXGqXMINGBq3Xc9aCIz5C+jr8uJF4ARUC/KU7sxAfIIVhau49K0NwJDiRduo5hvk; Received: from pool-74-96-233-244.washdc.fios.verizon.net ([74.96.233.244] helo=[192.168.1.54]) by host358.hostmonster.com with esmtpa (Exim 4.69) (envelope-from ) id 1P0OgE-000161-Rd for freebsd-performance@freebsd.org; Mon, 27 Sep 2010 19:08:27 -0600 Message-ID: <4CA14009.4050906@softhammer.net> Date: Mon, 27 Sep 2010 21:08:25 -0400 From: Stephen Sanders User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc13 Thunderbird/3.1.4 MIME-Version: 1.0 To: freebsd-performance@freebsd.org Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Identified-User: {2492:host358.hostmonster.com:softhamm:softhammer.net} {sentby:smtp auth 74.96.233.244 authed with ssanders@softhammer.net} Subject: gstripe small transaction size X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Sep 2010 01:35:07 -0000 I'm trying a disk throughput experiment where in two 3ware raid 6's are being put into a g_strip raid 0. The raid 6's are using 8 7200RPM disks. The disk transfer rate is ~80MB/s. Using a load generation tool that is using O_DIRECT for I/O, I've generated the following short output from iostat. Needless to say, the write performance is a lot less than I'm expecting. We've modified the kernel such that our KB/t figure is closer to 512KB/t per disk when measured without the g_strip. With g_strip turned on, the KB/t number is more like 60KB/t. The question is how do I get g_stripe to write larger transactions to the disk ? Thanks. gstripe label -v -s 131072 roadkill /dev/da0 /dev/da2 newfs /dev/stripe/roadkill mount /dev/stripe/roadkill /u8 sysctl kern.geom.stripe.fast=1 iostat -n3 -t da 5 tty da0 da1 da2 cpu tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id 0 200 39.52 13 0.49 11.97 1 0.01 41.23 12 0.49 0 0 0 0 100 0 47 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0 0 0 0 100 1 19 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0 0 0 0 100 20 47 0.00 0 0.00 41.43 3 0.11 0.00 0 0.00 0 0 0 0 100 0 18 56.60 1817 100.41 20.00 1 0.02 57.22 1797 100.44 0 0 6 1 93 0 16 58.87 1978 113.73 0.00 0 0.00 58.27 2000 113.81 0 0 6 1 92 0 16 60.38 1906 112.37 16.00 0 0.00 59.95 1918 112.31 0 0 7 1 92 0 16 59.36 1863 108.01 0.00 0 0.00 60.00 1844 108.07 0 0 6 1 93 0 16 59.88 1933 113.05 0.00 0 0.00 60.40 1915 112.98 0 0 7 1 92