From owner-freebsd-fs@FreeBSD.ORG Fri Jan 28 00:06:42 2005 Return-Path: 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 6870A16A4CE for ; Fri, 28 Jan 2005 00:06:42 +0000 (GMT) Received: from web41204.mail.yahoo.com (web41204.mail.yahoo.com [66.218.93.37]) by mx1.FreeBSD.org (Postfix) with SMTP id 0378C43D48 for ; Fri, 28 Jan 2005 00:06:42 +0000 (GMT) (envelope-from arne_woerner@yahoo.com) Received: (qmail 11486 invoked by uid 60001); 28 Jan 2005 00:06:41 -0000 Comment: DomainKeys? See http://antispam.yahoo.com/domainkeys DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; b=kbivopwtIsPrDaWkulQTIheAns+W6pT08IgENy8cTw6WqEKgK1bfIZake8F3iqCp5TiLnuIonJRyMvxIjfeDVSmkhCQWulGH030Z6q6/2n2PODXRTLBDL1PZCJmpRb6s0BeYTrL2elpPxmNyPC9eGae9cMRL/v26crqmLZaMF98= ; Message-ID: <20050128000641.11484.qmail@web41204.mail.yahoo.com> Received: from [213.54.138.99] by web41204.mail.yahoo.com via HTTP; Thu, 27 Jan 2005 16:06:41 PST Date: Thu, 27 Jan 2005 16:06:41 -0800 (PST) From: Arne "Wörner" To: freebsd-fs@FreeBSD.ORG In-Reply-To: <20050127040418.26913.qmail@web41205.mail.yahoo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Subject: Re: ufs+softupdates / consistency X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 28 Jan 2005 00:06:42 -0000 I would like to add, that I just tried my little performance test with KNOPPIX and fsync/openO_SYNC in a little C program. The results were even better (just about 3 seconds for 1000 64k blocks). With dd and the sync call it was about 6 seconds (btw.: Linux's sync waits until the harddisc acknowledged the write order requests). Since Linux's time command said, that the process was waiting for 90% of its alive-time, I believe, that the kernel was idle, too, because 1. sending the write order request is done quite quickly (I think), and 2. most of the time hard disc is busy with re-educating the magnetic layer of its discs without talking to the kernel, so that I do not fully understand the argument, that we should write just little chunks of data to the disc (is it because concurrent read/write requests (e. g.: a user process, that wants to read something, while the kernel syncs 64MB as soon as possible) might be delayed?). I would be glad, if somebody could tell me, if there is any work in progress or completed, that allows my old SEAGATE disc to perform as good as Linux allows it to perform. If not, I would like to fix the problem. -Arne Wörner __________________________________ Do you Yahoo!? Meet the all-new My Yahoo! - Try it today! http://my.yahoo.com