From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from merlin.infradead.org ([205.233.59.134]:41612 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754256Ab2FNHy6 (ORCPT ); Thu, 14 Jun 2012 03:54:58 -0400 Message-ID: <4FD998CE.3030705@kernel.dk> Date: Thu, 14 Jun 2012 09:54:54 +0200 From: Jens Axboe MIME-Version: 1.0 Subject: Re: FIO r/w to 2 disks References: <4E57E183169EA04186759995F13BDC621A18A7C7@FMSMSX103.amr.corp.intel.com> In-Reply-To: <4E57E183169EA04186759995F13BDC621A18A7C7@FMSMSX103.amr.corp.intel.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: fio-owner@vger.kernel.org List-Id: fio@vger.kernel.org To: "Strickland, Carl" Cc: "fio@vger.kernel.org" On 2012-06-08 21:52, Strickland, Carl wrote: > Hi All, > > I'm performing a series of time-based storage tests and need FIO to read and > write to separate disks, in the ratio specified (e.g. 80/20). > > I've performed initial tests with two FIO instances (one read, one write), but > found that in one scenario I get a ratio of ~50/50 and in another I get > ~60/40. However, in order to compare the results of these tests, their ratios > must be approximately equal. > > Is it possible to achieve this with a single FIO instance? Do you have any > recommendations for achieving a specific ratio with two FIO instances? It's not clear from your email exactly what kind of job(s) you ran. Have you tried a single job with rwmix set? rwmixread=80 and rw=randrw should give you the requested ratio, 80% reads and 20% writes. -- Jens Axboe