From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keld =?iso-8859-1?Q?J=F8rn?= Simonsen Subject: Re: raid1 - optimization Date: Thu, 3 Feb 2011 16:45:40 +0100 Message-ID: <20110203154540.GB27356@www2.open-std.org> References: <4D4AC231.8010900@anonymous.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4D4AC231.8010900@anonymous.org.uk> Sender: linux-raid-owner@vger.kernel.org To: John Robinson Cc: Roberto Spadim , Linux-RAID List-Id: linux-raid.ids On Thu, Feb 03, 2011 at 02:56:49PM +0000, John Robinson wrote: > On 03/02/2011 14:37, Roberto Spadim wrote: > >hi guys, i another thread i read about SNIA DDF Technical Position v2.0 > >could we implement RAID-1E, for sequencial/random read speedup? > >http://www.snia.org/tech_activities/standards/curr_standards/ddf/SNIA_DDF_Technical_Position_v2.0.pdf > >after that, could we implement some tweaks on read balance (there's > >another thread just for it) > > Those RAID-1E layouts look to me like what's implemented in md RAID as > RAID-10 with near and offset layouts. > > As discussed frequently here, md RAID-10 also has a far layout which can > provide slightly faster than RAID-0 throughput for sequential reading > with slightly slower than RAID-1 throughput for sequential writing. > Please see some of the benchmarks that have also been referred to on > this list in the last couple of days. I have written SNIA over a year ago on raid10,f2 to have it to be a standardized layout too, but without any response. Best regards Keld