From owner-freebsd-current@FreeBSD.ORG Sun May 23 10:15:31 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from green.homeunix.org (freefall.freebsd.org [216.136.204.21]) by hub.freebsd.org (Postfix) with ESMTP id 8F05316A4CE; Sun, 23 May 2004 10:15:31 -0700 (PDT) Received: from green.homeunix.org (green@localhost [127.0.0.1]) by green.homeunix.org (8.12.11/8.12.11) with ESMTP id i4NHFUJk062510; Sun, 23 May 2004 13:15:30 -0400 (EDT) (envelope-from green@green.homeunix.org) Received: (from green@localhost) by green.homeunix.org (8.12.11/8.12.11/Submit) id i4NHFUiG062509; Sun, 23 May 2004 13:15:30 -0400 (EDT) (envelope-from green) Date: Sun, 23 May 2004 13:15:29 -0400 From: Brian Feldman To: Poul-Henning Kamp Message-ID: <20040523171529.GF51125@green.homeunix.org> References: <20040521224729.680285D0A@ptavv.es.net> <45922.1085211971@critter.freebsd.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <45922.1085211971@critter.freebsd.dk> User-Agent: Mutt/1.5.6i cc: freebsd-current@freebsd.org Subject: Re: Disk performance under CURRENT X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 23 May 2004 17:15:31 -0000 On Sat, May 22, 2004 at 09:46:11AM +0200, Poul-Henning Kamp wrote: > In message <20040521224729.680285D0A@ptavv.es.net>, "Kevin Oberman" writes: > >I just ran test of disk writing performance under V4 (STABLE) and V5 > >(CURRENT) and was surprised at the difference. > > > >The test was simple and not at all rigorous. Just a dd bs=256k > >if=/dev/zero of=/dev/ad2. This is about the simplest way of dealing with > >a disk. No file system or anything else. Just raw data to the device. > > > >Under STABLE, I get an average of 25 MB/sec to the disk. Under CURRENT, > >it drops to 15 MB/sec. I did this because I had noted that it was now > >taking over an hour to backup my system disk (40 GB) when it was only > >taking 40 minutes when I was running V4.6. The STABLE system was built > >yesterday. The CURRENT system last Sunday. > > > >Any idea why this is so much slower? It looks to me like it must be in > >either geom or the disk driver. > > GEOM is slower than 4-stable in a degenerate case like this, but it > sounds to me like there is something else involved here too. Have > you removed WITNESS from your kernel ? Yeah, perhaps something else like using /dev/ad2 which is a bdev in -STABLE but cdev in -CURRENT? -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green@FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\