From owner-freebsd-current Sun Mar 22 16:55:01 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id QAA10597 for freebsd-current-outgoing; Sun, 22 Mar 1998 16:55:01 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from sendero.simon-shapiro.org (sendero-fddi.Simon-Shapiro.ORG [206.190.148.2]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id QAA10564 for ; Sun, 22 Mar 1998 16:54:47 -0800 (PST) (envelope-from shimon@simon-shapiro.org) Received: (qmail 28332 invoked from network); 23 Mar 1998 01:00:18 -0000 Received: from localhost.simon-shapiro.org (HELO sendero-fxp0.simon-shapiro.org) (@127.0.0.1) by localhost.simon-shapiro.org with SMTP; 23 Mar 1998 01:00:18 -0000 Message-ID: X-Mailer: XFMail 1.3-alpha-031798 [p0] on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 In-Reply-To: <199803222340.QAA00401@usr06.primenet.com> Date: Sun, 22 Mar 1998 17:00:18 -0800 (PST) Reply-To: shimon@simon-shapiro.org Organization: The Simon Shapiro Foundation From: Simon Shapiro To: Terry Lambert Subject: Re: CURRENT Kernel Status Cc: current@FreeBSD.ORG, root@danberlin.resnet.rochester.edu, toor@dyson.iquest.net, (Karl Denninger) Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG ... > For data you care about, you should use a two stage commit process that > guarantees an ordered set of operations, and forces a commit to stable > storage. > > Ideally, you'd do this by mounting the FS you were operating against > "sync" and implementing comething very like soft updates, except your > graph edges would be described by events important to you, not the FS. > 8-). Although an excellent idea (not necessarily new :-), this will not protect you from software bugs. Nothing will. > The way in which the current damage took place, where vm object commits > were not reliable... well, that's not something you can recover from at > all, sorry. You are right. This braught to mind to question the necessity of having a unified buffer I/O subsystem. In a truely compartmentalized system, the VM could have had nothing to do with data files I/O. Yet, even that would not have saved us from a bug. One of the virtues of Unix is a unified kernel. Any bug effectes any system. Simon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message