From owner-freebsd-hackers@FreeBSD.ORG Wed Jan 14 13:32:42 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 86E2416A4CE; Wed, 14 Jan 2004 13:32:42 -0800 (PST) Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id 99F1643D1D; Wed, 14 Jan 2004 13:32:40 -0800 (PST) (envelope-from phk@phk.freebsd.dk) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.10/8.12.10) with ESMTP id i0ELWWdN029578; Wed, 14 Jan 2004 22:32:32 +0100 (CET) (envelope-from phk@phk.freebsd.dk) To: Lukas Ertl From: "Poul-Henning Kamp" In-Reply-To: Your message of "Wed, 14 Jan 2004 22:27:25 +0100." <20040114215347.P608@korben.in.tern> Date: Wed, 14 Jan 2004 22:32:32 +0100 Message-ID: <29577.1074115952@critter.freebsd.dk> cc: Greg 'groggy' Lehey cc: Mark Linimon cc: hackers@freebsd.org cc: Robert Watson Subject: Re: Future of RAIDFrame and Vinum (was: Future of RAIDFrame) X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 14 Jan 2004 21:32:42 -0000 In message <20040114215347.P608@korben.in.tern>, Lukas Ertl writes: >On Mon, 12 Jan 2004, Robert Watson wrote: > >> I think the right strategy is to follow the minimalist approach now >> (adopt the disk(9) API, rather than having Vinum generate character >> devices) so that swap works on Vinum again, and so that when UFS moves >> to speaking GEOM there's no loss of functionality. If we want to >> completely reimplement Vinum, we should do that separately so as to >> avoid loss of functionality during structural changes. > >As many ways lead to Rome, how about the following scenario. I don't know >if it's a clever way to do things, and I don't know if it's even possible >to with GEOM, so some input is appreciated. > >*) Have separate GEOM classes for each of the different vinum objects > (drive, sd, plex, volume). >*) Let the drive geom taste the slices configured for vinum, read the > on-disk config and then spawn the necessary other geoms (I'm not sure > if the latter can be done in GEOM). >*) I think this is a clean implementation, since the GEOM framework offers > all the "background" needed to transform the IO requests. >*) It would also be a good way to clean up the vinum code. It is possible in GEOM, but I am not convinced that fragmenting into this many GEOM classes can be classified as an easy path to go. I think for now the important thing is to get the people interested on this collected on a mail-alias, and for them to discuss how the can work together to make something happen. After that, try to define "something" closer. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.