From owner-cvs-all@FreeBSD.ORG Wed Jun 18 12:53:53 2003 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 4797937B404 for ; Wed, 18 Jun 2003 12:53:53 -0700 (PDT) Received: from rootlabs.com (root.org [67.118.192.226]) by mx1.FreeBSD.org (Postfix) with SMTP id 8CB4F43FAF for ; Wed, 18 Jun 2003 12:53:51 -0700 (PDT) (envelope-from nate@rootlabs.com) Received: (qmail 57028 invoked by uid 1000); 18 Jun 2003 19:53:52 -0000 Date: Wed, 18 Jun 2003 12:53:52 -0700 (PDT) From: Nate Lawson To: Poul-Henning Kamp In-Reply-To: <20030618092938.2E5FC37B418@hub.freebsd.org> Message-ID: <20030618125009.K56972@root.org> References: <20030618092938.2E5FC37B418@hub.freebsd.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: cvs-src@FreeBSD.org cc: src-committers@FreeBSD.org cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/geom geom_fox.c src/sys/modules/geomMakefile src/sys/modules/geom/geom_fox Makefile src/sys/conf NOTES files options X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 Jun 2003 19:53:53 -0000 On Wed, 18 Jun 2003, Poul-Henning Kamp wrote: > Add "GEOM_FOX", a class which detects and selects between multiple > redundant paths to the same device. > > This class reacts to a label in the first sector of the device, > which is created the following way: > > # "0123456789abcdef012345..." > # "<----magic-----><-id-...> > echo "GEOM::FOX someid" | dd of=/dev/da0 conv=sync This looks interesting. Have you shown this to gordon@ who is adding something similar to FFS? It might be good to have a generalized config tool. Won't the location you've chosen interfere with an MBR on i386 drives? Is it possible to pick another space (i.e. FFS label, {bsd,sun}label fields, GPT)? > NB: Since the fact that multiple disk devices are in fact the same > device is not known to GEOM, the geom taste/spoil process cannot > fully catch all corner cases and this module can therefore be > confused if you do the right wrong things. > > NB: The disk level drivers need to do the right thing for this to > be useful, and that is not by definition currently the case. You're right in that it will be a while before disk devices handle multipathing themselves. It would be great if you could help with making device_t support this kind of operation. -Nate