From mboxrd@z Thu Jan 1 00:00:00 1970 From: Justin Piszcz Subject: Re: below 10MB/s write on raid5 Date: Mon, 11 Jun 2007 10:07:24 -0400 (EDT) Message-ID: References: <200706111446.55813.Dexter.Filmore@gmx.de> <200706111528.11828.Dexter.Filmore@gmx.de> <200706111606.11006.Dexter.Filmore@gmx.de> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Return-path: In-Reply-To: <200706111606.11006.Dexter.Filmore@gmx.de> Sender: linux-raid-owner@vger.kernel.org To: Dexter Filmore Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Mon, 11 Jun 2007, Dexter Filmore wrote: >> 10gb read test: >> >> dd if=/dev/md0 bs=1M count=10240 of=/dev/null >> >> What is the result? > > 71,7MB/s - but that's reading to null. *writing* real data however looks quite > different. > >> >> I've read that LVM can incur a 30-50% slowdown. >> > Even then the 8-10MB/s I get would be a little low. > > > > -- > -----BEGIN GEEK CODE BLOCK----- > Version: 3.12 > GCS d--(+)@ s-:+ a- C++++ UL++ P+>++ L+++>++++ E-- W++ N o? K- > w--(---) !O M+ V- PS+ PE Y++ PGP t++(---)@ 5 X+(++) R+(++) tv--(+)@ > b++(+++) DI+++ D- G++ e* h>++ r* y? > ------END GEEK CODE BLOCK------ > > http://www.stop1984.com > http://www.againsttcpa.com > Would it be possible to trash the LVM and write directly to the MD device? I'd be really curious to see what it gets with XFS ontop of MD. Justin.