From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Dillow Subject: Re: [Scst-devel] Integration of SCST in the mainstream Linux kernel Date: Thu, 31 Jan 2008 13:12:15 -0500 Message-ID: <1201803135.21160.8.camel@lap75545.ornl.gov> References: <20080130083239E.fujita.tomonori@lab.ntt.co.jp> <20080130195635T.tomof@acm.org> <1201785938.7280.105.camel@haakon2.linux-iscsi.org> <47A1EE54.6000005@vlnb.net> <47A1F67C.4020300@scalableinformatics.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-reply-to: Sender: linux-kernel-owner@vger.kernel.org To: Bart Van Assche Cc: landman@scalableinformatics.com, Vladislav Bolkhovitin , James.Bottomley@hansenpartnership.com, linux-scsi@vger.kernel.org, rdreier@cisco.com, linux-kernel@vger.kernel.org, "Nicholas A. Bellinger" , fujita.tomonori@lab.ntt.co.jp, scst-devel@lists.sourceforge.net, akpm@linux-foundation.org, FUJITA Tomonori , torvalds@linux-foundation.org List-Id: linux-scsi@vger.kernel.org On Thu, 2008-01-31 at 18:08 +0100, Bart Van Assche wrote: > If anyone has a suggestion for a better test than dd to compare the > performance of SCSI storage protocols, please let it know. xdd on /dev/sda, sdb, etc. using -dio to do direct IO seems to work decently, though it is hard (ie, impossible) to get a repeatable sequence of IO when using higher queue depths, as it uses threads to generate multiple requests. You may also look at sgpdd_survey from Lustre's iokit, but I've not done much with that -- it uses the sg devices to send lowlevel SCSI commands. I've been playing around with some benchmark code using libaio, but it's not in generally usable shape. xdd: http://www.ioperformance.com/products.htm Lustre IO Kit: http://manual.lustre.org/manual/LustreManual16_HTML/DynamicHTML-20-1.html -- Dave Dillow National Center for Computational Science Oak Ridge National Laboratory (865) 241-6602 office