From owner-freebsd-current Tue Mar 12 3: 2:18 2002 Delivered-To: freebsd-current@freebsd.org Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163]) by hub.freebsd.org (Postfix) with ESMTP id C6E3E37B436 for ; Tue, 12 Mar 2002 03:02:06 -0800 (PST) Received: from critter.freebsd.dk (localhost [127.0.0.1]) by critter.freebsd.dk (8.12.2/8.12.2) with ESMTP id g2CB1Znp001848; Tue, 12 Mar 2002 12:01:44 +0100 (CET) (envelope-from phk@critter.freebsd.dk) To: Rasmus Skaarup Cc: current@FreeBSD.ORG Subject: Re: GEOM code ready for testing In-Reply-To: Your message of "Tue, 12 Mar 2002 11:58:02 +0100." <20020312114526.G17904-100000@skaarup.org> Date: Tue, 12 Mar 2002 12:01:35 +0100 Message-ID: <1847.1015930895@critter.freebsd.dk> From: Poul-Henning Kamp 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 In message <20020312114526.G17904-100000@skaarup.org>, Rasmus Skaarup writes: > >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? Basically when a new "g_provider" is created it is offered to each method in turn and if that method likes it, it can stick g_geom on top of it. How you would recognize the same disk on thre different paths is a good question. We could implement (if we don't already have it) an ioctl/BIO_GETATTR which returns the serial number(s) of the diskdevice and you could query that. -- 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. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message