From owner-freebsd-hackers Mon Feb 16 12:52:50 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id MAA24592 for freebsd-hackers-outgoing; Mon, 16 Feb 1998 12:52:50 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from sendero.simon-shapiro.org (sendero-fxp0.Simon-Shapiro.ORG [206.190.148.34]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id MAA24518 for ; Mon, 16 Feb 1998 12:52:32 -0800 (PST) (envelope-from shimon@sendero-fxp0.simon-shapiro.org) Received: (qmail 4329 invoked by uid 1000); 16 Feb 1998 20:58:47 -0000 Message-ID: X-Mailer: XFMail 1.3-alpha-020998 [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: <3.0.32.19691231210000.00a226f0@pop.mpc.com.br> Date: Mon, 16 Feb 1998 12:58:47 -0800 (PST) Reply-To: shimon@simon-shapiro.org Organization: The Simon Shapiro Foundation From: Simon Shapiro To: Capriotti Subject: Re: SFT Cc: hackers@FreeBSD.ORG Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On 14-Feb-98 Capriotti wrote: > Hey, boys, just one question that crossed my mind: > > Why can't the kernel do something like: > > > (consider a system w/ mirrowed disks using ccd) > > if (main disk) fails then start using (mirror disk) > > What - technically - prevents ccd/kernel/something else from being able > to > do it ? > > At 11:33 AM 1/6/98 -0800, you wrote: >> >>On Tue, 6 Jan 1998, Capriotti wrote: >> >>> Does anyone have any news about System Fault Tolerance under Free ? >>> >>> Like what Novell has, from mirrowed disks to mirrowed servers ? >> >> Mirrored disks can be done with ccd. I am working on these issues. They are not as simple as one would have liked them to be. My proposed solution will come in several flavours: a. Fault Resilient; Where hardware failure does not destroy the data, and common hardware problems can be survived without disruption of service. b. High Availability; Where the system does not have a SPOF (single Point Of Failure), and can detect failures, and swith over processing from a failed component to a healthy component. c. Fault Tolerant; Where a single failure will not discrupt the service, which will be able to continue, in a manner transparent to external users. My plan is to have options a. & b. available before April 1998, and option c. by year end. I am planning on directing much of this discussion (unless told otherwise) to freebsd-database, as this is typically where the most interested audience should be, and since many of the tools developed have one thing or another to do with database technology. ---------- Sincerely Yours, Simon Shapiro Shimon@Simon-Shapiro.ORG Voice: 503.708.7858 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message