From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keld =?iso-8859-1?Q?J=F8rn?= Simonsen Subject: Re: help with bad performing raid6 Date: Fri, 31 Jul 2009 20:21:18 +0200 Message-ID: <20090731182118.GB11756@rap.rap.dk> References: <72dbd3150907301409t5ea20979gcf400e4c53a32d62@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Return-path: Content-Disposition: inline In-Reply-To: <72dbd3150907301409t5ea20979gcf400e4c53a32d62@mail.gmail.com> Sender: linux-raid-owner@vger.kernel.org To: David Rees Cc: Jon Nelson , LinuxRaid List-Id: linux-raid.ids On Thu, Jul 30, 2009 at 02:09:19PM -0700, David Rees wrote: > On Mon, Jul 27, 2009 at 12:19 PM, Jon Nelson wrote: > > When I say "bad performance" I mean writes that vary down to 100KB/s > > or less, as reported by rsync. The "average" end-to-end speed for > > writing large (500MB to 5GB) files hovers around 3-4MB/s. This is over > > 100 MBit. > > That doesn't sound too unexpected. rsync does a lot of reading and > writing, so you're going to see less than network speeds. rsync also does a lot of computing, so that is also a source of delay. For faster cpu's the delay is not so big. I get near network speed ( 80 Mbit/s on a 100 Mbit/s LAN) between two of my faster machines. best regards keld