From owner-freebsd-current@FreeBSD.ORG Mon Oct 10 01:26:32 2011 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8927D106566B; Mon, 10 Oct 2011 01:26:32 +0000 (UTC) (envelope-from jwd@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 58AFD8FC08; Mon, 10 Oct 2011 01:26:32 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.4/8.14.4) with ESMTP id p9A1QWAT042241; Mon, 10 Oct 2011 01:26:32 GMT (envelope-from jwd@freefall.freebsd.org) Received: (from jwd@localhost) by freefall.freebsd.org (8.14.4/8.14.4/Submit) id p9A1QV3M042240; Mon, 10 Oct 2011 01:26:31 GMT (envelope-from jwd) Date: Mon, 10 Oct 2011 01:26:31 +0000 From: John To: Miroslav Lachman <000.fbsd@quip.cz> Message-ID: <20111010012631.GA45500@FreeBSD.org> References: <344794801.20111005101957@serebryakov.spb.ru> <4E8C1426.60107@quip.cz> <251861322.20111005125825@serebryakov.spb.ru> <4E8C6E85.90005@quip.cz> <4E8CD662.90202@quip.cz> <4E8DA627.60003@quip.cz> <711721489.20111006175611@serebryakov.spb.ru> <4E919DFF.8090607@quip.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4E919DFF.8090607@quip.cz> User-Agent: Mutt/1.4.2.3i Cc: freebsd-current@FreeBSD.org, lev@FreeBSD.org, Ivan Voras , freebsd-geom@FreeBSD.org Subject: Re: RFC: Project geom-events X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Oct 2011 01:26:32 -0000 ----- Miroslav Lachman's Original Message ----- > Lev Serebryakov wrote: > >Hello, Miroslav. > >You wrote 6 ?????????????? 2011 ??., 16:59:19: > > [...] > > >>The current state is simply wrong, because user can do something what > >>cannot work and is not documented anywhere. > > It is Ok in UNIX way, in general. You should be able to shoot your > > leg, it is good :) > > I am sorry for my late reply. > Foot shooting is OK, if somebody wants to shoot his foot, but I don't > want to shoot my foot if I am aiming at my head :) > > > But if geom_label doesn't reduce its provider to count its own > > metadata, it looks like a bug! > > As Ivan Voras explained, it is not a bug, it is just a matter of mixing > two things thant can't coexist together. So the problem is that it is > not mentioned anywhere in the FreeBSD docs. (Thank you Ivan for your > explanation!) > And as somebody else already mentioned in this thread, it should be > documented in manpages and Handbook and gpart should show warning > message if user is trying to put GPT on non real disk devices. > > As is mentioned in the thread "Memstick image differences between 8.x > and 9.x", the GPT brings more problems by requirement of second table at > the end of the device (so disk image cannot be easily written by dd on > bigger disk) This also seem to prevent something useful like: # camcontrol inquiry da0 pass2: Fixed Direct Access SCSI-5 device pass2: Serial Number 3TB1BKGX00009036W9EN pass2: 600.000MB/s transfers, Command Queueing Enabled # camcontrol inquiry da25 pass27: Fixed Direct Access SCSI-5 device pass27: Serial Number 3TB1BKGX00009036W9EN pass27: 600.000MB/s transfers, Command Queueing Enabled # gmultipath label ZFS0 da0 da25 # gpart create -s gpt $device # gpart add -s 128 -t freebsd-boot $device # Create 64K boot partition # gpart add -s 4m -t freebsd-ufs -l mb$dev $device # small partition # gpart add -t freebsd-zfs -l $dev $device # Remaining space for zfs It seems like protecting your partitions with multiple paths would be a good thing. I've been experimenting with this and end up with corrupt partitions. Am I missing something? -john