From owner-freebsd-performance@FreeBSD.ORG Sat Mar 3 10:09:47 2007 Return-Path: X-Original-To: freebsd-performance@freebsd.org Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 834CC16A405 for ; Sat, 3 Mar 2007 10:09:47 +0000 (UTC) (envelope-from alexander@leidinger.net) Received: from redbull.bpaserver.net (redbullneu.bpaserver.net [213.198.78.217]) by mx1.freebsd.org (Postfix) with ESMTP id 3DEC113C491 for ; Sat, 3 Mar 2007 10:09:47 +0000 (UTC) (envelope-from alexander@leidinger.net) Received: from outgoing.leidinger.net (p54A5F2C9.dip.t-dialin.net [84.165.242.201]) by redbull.bpaserver.net (Postfix) with ESMTP id BB0AA2E1AE; Sat, 3 Mar 2007 11:09:43 +0100 (CET) Received: from Magellan.Leidinger.net (Magellan.Leidinger.net [192.168.1.1]) by outgoing.leidinger.net (Postfix) with ESMTP id 000325B4817; Sat, 3 Mar 2007 11:09:40 +0100 (CET) Date: Sat, 3 Mar 2007 11:09:40 +0100 From: Alexander Leidinger To: Alan Amesbury Message-ID: <20070303110940.32893388@Magellan.Leidinger.net> In-Reply-To: <45E8B994.2010100@umn.edu> References: <20070302120018.5830716A4A9@hub.freebsd.org> <45E8B994.2010100@umn.edu> X-Mailer: Claws Mail 2.8.0 (GTK+ 2.10.9; i686-portbld-freebsd7.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BPAnet-MailScanner-Information: Please contact the ISP for more information X-BPAnet-MailScanner: Found to be clean X-BPAnet-MailScanner-SpamCheck: not spam, SpamAssassin (not cached, score=-14.864, required 8, autolearn=not spam, BAYES_00 -15.00, DK_POLICY_SIGNSOME 0.00, FORGED_RCVD_HELO 0.14) X-BPAnet-MailScanner-From: alexander@leidinger.net X-Spam-Status: No Cc: freebsd-performance@freebsd.org Subject: Re: (S)ATA performance in FBSD 6.2/7.0 X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 03 Mar 2007 10:09:47 -0000 Quoting Alan Amesbury (Fri, 02 Mar 2007 17:56:04 -0600): > Looking at /usr/include/sys/mount.h, I see that there are two flags > defined: MNT_SYNCHRONOUS and MNT_ASYNC. I'm not sure why both flags > exist, but suspect the former was added so you could mount UFS/FFS/UFS2 > filesystems that had soft updates enabled in synchronous mode without > having to umount the filesystem, use tunefs(8)'s "-n" flag to > enable/disable soft updates, then remount the filesystem with the > appropriate flag(s). In FreeBSD we have 3 types, not 2. We have "sync", "noasync" (default) and "async". With noasync the meta-data is written in sync mode and the data is written in async mode. For async the complete IO is done asynchronous (the meta-data too). And for sync the complete IO is synchronous. mount(8) tells this with some more words. Bye, Alexander. -- As a math atheist, I should be excused from this. -- Calvin http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7 http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137