From owner-freebsd-current Tue Mar 12 9:34:55 2002 Delivered-To: freebsd-current@freebsd.org Received: from panzer.kdm.org (panzer.kdm.org [216.160.178.169]) by hub.freebsd.org (Postfix) with ESMTP id 51A9537B405 for ; Tue, 12 Mar 2002 09:34:37 -0800 (PST) Received: (from ken@localhost) by panzer.kdm.org (8.11.6/8.9.1) id g2CHYNl79883; Tue, 12 Mar 2002 10:34:23 -0700 (MST) (envelope-from ken) Date: Tue, 12 Mar 2002 10:34:23 -0700 From: "Kenneth D. Merry" To: Rasmus Skaarup Cc: Poul-Henning Kamp , current@FreeBSD.ORG Subject: Re: GEOM code ready for testing Message-ID: <20020312103423.A79424@panzer.kdm.org> References: <47305.1015913090@critter.freebsd.dk> <20020312114526.G17904-100000@skaarup.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20020312114526.G17904-100000@skaarup.org>; from mfbsd@skaarup.org on Tue, Mar 12, 2002 at 11:58:02AM +0100 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Tue, Mar 12, 2002 at 11:58:02 +0100, Rasmus Skaarup wrote: > On Tue, 12 Mar 2002, Poul-Henning Kamp wrote: > > In message <1015887527.74983.41.camel@newton.aipo.gov.au>, Carl Makin writes: > > > >On Mon, 2002-03-11 at 06:34, Poul-Henning Kamp wrote: > > > > > >> The GEOM code is now ready for early testing: > > > > > >Would GEOM support accessing a device via multiple paths? (ie could we > > >write a method that would do that?) > > > > Yes, that would be possible. > > Have you given any thought to how that might be implemented? If somekind > of ID is required to identify the same disk via multiple paths, in which > part of GEOM will this be implemented? > > I can't figure out from your documentation whether you have somekind of > "Master GEOM" instance that initiates the device recognition, or otherwise > how is this initiated? FWIW, Justin and I have been thinking about (for years, actually) doing multipath support inside CAM. We would figure out that a device is unique via a serial number or WWN. There would probably also be a manual identification method that would allow the user to specify that a given device can be accessed via multiple routes. That would be useful for devices without a unique serial number. For disks, probably the best thing to do is to have some sort of label on the disk and use that to determine which disks are the same. Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message