From owner-freebsd-questions@FreeBSD.ORG Fri Nov 12 07:39:49 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 99AA2106564A for ; Fri, 12 Nov 2010 07:39:49 +0000 (UTC) (envelope-from smithi@nimnet.asn.au) Received: from sola.nimnet.asn.au (paqi.nimnet.asn.au [115.70.110.159]) by mx1.freebsd.org (Postfix) with ESMTP id 15EAA8FC1A for ; Fri, 12 Nov 2010 07:39:48 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by sola.nimnet.asn.au (8.14.2/8.14.2) with ESMTP id oAC7dgbM082953; Fri, 12 Nov 2010 18:39:43 +1100 (EST) (envelope-from smithi@nimnet.asn.au) Date: Fri, 12 Nov 2010 18:39:42 +1100 (EST) From: Ian Smith To: Derek Funk In-Reply-To: <20101112004729.7F733106578D@hub.freebsd.org> Message-ID: <20101112181758.O76697@sola.nimnet.asn.au> References: <20101112004729.7F733106578D@hub.freebsd.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: freebsd-questions@freebsd.org Subject: Re: GPT Question X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Nov 2010 07:39:49 -0000 In freebsd-questions Digest, Vol 336, Issue 9, Message: 23 On Thu, 11 Nov 2010 17:45:19 -0600 Derek Funk wrote: > On 11/10/2010 9:34 PM, Mark Caudill wrote: [..] > > just ran `dd if=/dev/zero of=/dev/ad12 bs=512` and let it run. That must > > have done the trick because I was then able to partition the disk in > > sysinstall and all is well. What I'm wondering is what really went on > > here? I'm not clear at all as to why FreeBSD (or some mechanism within > > this installation) isn't able to handle this. Or was this a GPT issue at > > all? I'd like to find out what was going on so that I don't chase my > > tail again on issues like this in the future. Thanks. > My understanding is, if you are using FreeBSD 8.x, sysinstall / fdisk > will not write disk partitions. gpart is used now. Your understanding is incorrect. In 8.x you MAY use gpart now, but sysinstall (when running as init from a booted installation medium) still slices and partitions disks fine, and sysinstall - or sade(8) - (when run as a utility from a working system) will indeed write to the boot sectors including MBR, and will happily slice and partition disk/s other than the boot slice, if and only if you have previously set sysctl kern.geom.debugflags=16 - not called the 'foot-shooting' bit for nothing - so don't forget to set it back to 0 when you've finished. cheers, Ian