From owner-freebsd-fs@FreeBSD.ORG Sat Oct 29 22:26:44 2005 Return-Path: X-Original-To: freebsd-fs@FreeBSD.ORG Delivered-To: freebsd-fs@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 96F2016A41F for ; Sat, 29 Oct 2005 22:26:44 +0000 (GMT) (envelope-from jp@devnull.cz) Received: from mail.mynet.cz (mail.mynet.cz [195.122.208.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id 0BDC343D46 for ; Sat, 29 Oct 2005 22:26:43 +0000 (GMT) (envelope-from jp@devnull.cz) Received: from [192.168.1.29] (r2g242.chello.upc.cz [62.245.70.242]) by mail.mynet.cz (8.12.11/8.12.11) with ESMTP id j9TMUcK7076168 (version=TLSv1/SSLv3 cipher=DHE-DSS-AES256-SHA bits=256 verify=NO) for ; Sun, 30 Oct 2005 00:30:39 +0200 (CEST) (envelope-from jp@devnull.cz) Date: Sun, 30 Oct 2005 00:26:35 +0200 (CEST) From: Jan Pechanec X-X-Sender: jp@axxem.in.idc.cz To: FreeBSD FS Mailing List Message-ID: <20051030000603.C11574@axxem.in.idc.cz> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Subject: initial writes with soft-updates X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 29 Oct 2005 22:26:44 -0000 hello all, could you please shed some light on this situation? When I create many files at once with soft updates enabled, I can see some initial writes (8 in this example) during the 1st second of the operation. After that, it's silent till the next sync() - which is expected. the whole operation takes 4-5 seconds on my not brand-new 500MHz machine so I just cannot understand those first writes. I know how soft updates work and that's why I can't understand it. The system is 5.3-RELEASE-p23, 128 MB RAM with 70 MB free at least, load is nearly zero - just the test running (load averages: 0.15, 0.03, 0.01). I don't think it's about version, I have to be missing something about soft updates, just don't know what it is. When I try it with just a few files (< 10), there is no immediate write. I'm looking into soft updates chapter of McKusick's book on FreeBSD right now and cannot find an answer there either. # time for i in `jot 1000`; do touch file-$i; done real 0m4.676s user 0m0.677s sys 0m3.931s # iostat -c 100 -d ad0 14.25 8 0.11 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 please CC: on me, I'm not already a member of this list. thank you, j. -- Jan Pechanec http://www.devnull.cz