From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andras Korn Subject: Re: write-behind has no measurable effect? Date: Tue, 15 Feb 2011 13:40:26 +0100 Message-ID: <20110215124026.GC13135@hellgate.intra.guy> References: <20110214213817.GG836@hellgate.intra.guy> <20110215095042.51ef7e0a@notabene.brown> <20110214225754.GK19990@hellgate.intra.guy> <20110215104109.06b12b33@notabene.brown> <20110215010052.GA13135@hellgate.intra.guy> <4D59D4A5.9050106@anonymous.org.uk> <20110215021900.GB13135@hellgate.intra.guy> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Tue, Feb 15, 2011 at 06:10:17AM -0300, Roberto Spadim wrote: > andras could you make some benchmarks to raid1 with round robin read balance? > at this site: > www.spadim.com.br/raid1/ > > it's kernel 2.6.37 based Yes, I can do that. Can you give me some hints on what specific configuration to try? I see you have some sysfs tunables. My raid1 array consists of two spinning disks and an SSD, all local. Do you expect this patch to make a difference in my case? With the spinning disks marked as write-mostly, I'm getting close to the read performance of the SSD (except for very small random reads, for some reason). It's random writes that are much slower than with only the SSD. -- Andras Korn There is no spoon(). But there is a fork().