From owner-freebsd-current@FreeBSD.ORG Mon May 24 09:19:20 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1A71916A4CE; Mon, 24 May 2004 09:19:20 -0700 (PDT) Received: from postal3.es.net (postal3.es.net [198.128.3.207]) by mx1.FreeBSD.org (Postfix) with ESMTP id EF8E343D49; Mon, 24 May 2004 09:19:19 -0700 (PDT) (envelope-from oberman@es.net) Received: from ptavv.es.net ([198.128.4.29]) by postal3.es.net (Postal Node 3) with ESMTP (SSL) id IBA74465; Mon, 24 May 2004 09:17:27 -0700 Received: from ptavv (localhost [127.0.0.1]) by ptavv.es.net (Tachyon Server) with ESMTP id DC2305D08; Mon, 24 May 2004 09:17:26 -0700 (PDT) To: Scott Long In-reply-to: Your message of "Sat, 22 May 2004 09:36:18 MDT." <40AF7372.30902@freebsd.org> Date: Mon, 24 May 2004 09:17:26 -0700 From: "Kevin Oberman" Message-Id: <20040524161726.DC2305D08@ptavv.es.net> 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: Mon, 24 May 2004 16:19:20 -0000 > Date: Sat, 22 May 2004 09:36:18 -0600 > From: Scott Long > > Kevin Oberman wrote: > > 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. > > Btw, before we run off and dig into performance work here, can you send > the output of the following from your test machine: > > sysctl debug.witness_watch Sorry, but I've been off-line for a while on travel. And my wireless card died. :-( In any case, by kernel is built without witness, so I get sysctl: unknown oid 'debug.witness_watch'. The system is a UP P4-M and not running APIC. No INVARIANTS, either. -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 -- R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634