From owner-freebsd-stable@FreeBSD.ORG Wed Jan 14 05:11:46 2004 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 652C716A4CE for ; Wed, 14 Jan 2004 05:11:46 -0800 (PST) Received: from osku.suutari.iki.fi (osku.syncrontech.com [213.28.98.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id B52C343D66 for ; Wed, 14 Jan 2004 05:11:40 -0800 (PST) (envelope-from ari@suutari.iki.fi) Received: from coffee.syncrontech.com (coffee.syncrontech.com [62.71.8.37]) by osku.suutari.iki.fi (8.12.8p1/8.12.8) with ESMTP id i0EDBVdf024584; Wed, 14 Jan 2004 15:11:31 +0200 (EET) (envelope-from ari@suutari.iki.fi) From: Ari Suutari Organization: At Home To: Raymond Wiker , freebsd-stable@freebsd.org Date: Wed, 14 Jan 2004 15:11:30 +0200 User-Agent: KMail/1.5.4 References: <200401141453.50150.ari@suutari.iki.fi> <16389.15817.322098.577889@raw.grenland.fast.no> In-Reply-To: <16389.15817.322098.577889@raw.grenland.fast.no> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200401141511.30958.ari@suutari.iki.fi> Subject: Re: Adaptect raid performance with FreeBSD X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Jan 2004 13:11:46 -0000 On Wednesday 14 January 2004 15:02, Raymond Wiker wrote: > Ari Suutari writes: > > dd if=/dev/rda1s1a of=/dev/null bs=1m count=100 > > 100+0 records in > > 100+0 records out > > 104857600 bytes transferred in 4.193832 secs (25002814 bytes/sec) > > > > So, I get only about 25MB/s. Shouldn't I be getting something > > like 70 MB/s, or even more since there are two disks that > > can server read requests ? > > Have you tried other block sizes? I think you may be able to > get better results by going to a lower block size (e.g, 64k instead of > 1m). Some experimentation will show which block size(s) work best. I tried with 32k, 64k, 256k and 512k. Speed is about the same with every block size. Block sizes less than 32k seem to give even worse performance. Ari S. -- Ari Suutari Lemi, Finland