From owner-freebsd-current@FreeBSD.ORG Fri May 21 15:47:31 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 8B70716A4CE for ; Fri, 21 May 2004 15:47:31 -0700 (PDT) Received: from postal1.es.net (postal1.es.net [198.128.3.205]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7E27243D2F for ; Fri, 21 May 2004 15:47:31 -0700 (PDT) (envelope-from oberman@es.net) Received: from ptavv.es.net ([198.128.4.29]) by postal1.es.net (Postal Node 1) with ESMTP (SSL) id IBA74465 for ; Fri, 21 May 2004 15:47:29 -0700 Received: from ptavv (localhost [127.0.0.1]) by ptavv.es.net (Tachyon Server) with ESMTP id 680285D0A for ; Fri, 21 May 2004 15:47:29 -0700 (PDT) To: freebsd-current@freebsd.org Date: Fri, 21 May 2004 15:47:29 -0700 From: "Kevin Oberman" Message-Id: <20040521224729.680285D0A@ptavv.es.net> Subject: 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: Fri, 21 May 2004 22:47:31 -0000 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. -- 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