From owner-freebsd-current Tue Mar 12 4:14:47 2002 Delivered-To: freebsd-current@freebsd.org Received: from skaarup.org (skaarup.org [130.228.230.140]) by hub.freebsd.org (Postfix) with SMTP id 4BBAB37B419 for ; Tue, 12 Mar 2002 04:14:40 -0800 (PST) Received: (qmail 19045 invoked by uid 0); 12 Mar 2002 12:14:38 -0000 Received: from localhost (HELO skaarup.org) (127.0.0.1) by localhost with SMTP; 12 Mar 2002 12:14:36 -0000 Received: (qmail 19030 invoked by uid 1039); 12 Mar 2002 12:14:35 -0000 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 12 Mar 2002 12:14:35 -0000 Date: Tue, 12 Mar 2002 13:14:35 +0100 (CET) From: Rasmus Skaarup To: Poul-Henning Kamp Cc: current@FreeBSD.ORG Subject: Re: GEOM code ready for testing In-Reply-To: <1847.1015930895@critter.freebsd.dk> Message-ID: <20020312130810.U18984-100000@skaarup.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Virus-Scanned: by AMaViS perl-11 @skaarup.org 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, 12 Mar 2002, Poul-Henning Kamp wrote: > 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: > > > >> >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? > > > > 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. Ahh.. But do you rule out the possibility that two methods could apply to a g_provider? Or is this even a problem? > 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. Hmm, but I'm not sure all kinds of storage devices have serialnumbers that could be fetched (tape devices for instance?) and can we rely on the hardware manufacturers to provide unique serialnumbers? Best regards, Rasmus Skaarup To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message