From owner-freebsd-hackers@FreeBSD.ORG Mon Feb 8 17:56:26 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5411E1065670 for ; Mon, 8 Feb 2010 17:56:26 +0000 (UTC) (envelope-from jhay@meraka.csir.co.za) Received: from zibbi.meraka.csir.co.za (zibbi.meraka.csir.co.za [IPv6:2001:4200:7000:2::1]) by mx1.freebsd.org (Postfix) with ESMTP id 82F908FC08 for ; Mon, 8 Feb 2010 17:56:25 +0000 (UTC) Received: by zibbi.meraka.csir.co.za (Postfix, from userid 3973) id B50DE3982D; Mon, 8 Feb 2010 19:56:21 +0200 (SAST) Date: Mon, 8 Feb 2010 19:56:21 +0200 From: John Hay To: Peter Steele Message-ID: <20100208175621.GA43054@zibbi.meraka.csir.co.za> References: <7B9397B189EB6E46A5EE7B4C8A4BB7CB383B2699@MBX03.exg5.exghost.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7B9397B189EB6E46A5EE7B4C8A4BB7CB383B2699@MBX03.exg5.exghost.com> User-Agent: Mutt/1.4.2.3i Cc: "freebsd-hackers@freebsd.org" Subject: Re: How can I force boot from alternate drive with boot.config? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Feb 2010 17:56:26 -0000 On Mon, Feb 08, 2010 at 10:25:54AM -0600, Peter Steele wrote: > I've asked this on the -questions list but haven't had any feedback. I have a system configured with multiple identical drives each loaded with FreeBSD. When I was using MBR partitioning, I could create a boot.config to force the system to boot from a specific drive. For example, if I wanted to boot from the second drive, I'd create a boot.config with: > > > > 1:ad(1,a)/boot/loader > > > > We've switched to GPT partitioning and I can't seem to find a way to do this same trick. The boot loader only seems to recognize MBR partitions when it comes to this feature. I looked at the boot.c source code and there doesn't seem to be anything specifically related to GPT partitioning. I cannot for example say something like: > > > > 1:ad(1,p3)/boot/loader > > > > where p3 is the root partition in my GPT partitioned drives. So I'm puzzled: If I have a two drive system with BSD loaded on both drives and the drives are configured with GPT partitions, how can I force the system to boot from the second drive using boot.config? > I use: ad(0p3)/boot/loader John -- John Hay -- jhay@meraka.csir.co.za / jhay@FreeBSD.org