From owner-freebsd-questions@FreeBSD.ORG Tue Oct 28 12:22:38 2008 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 028D21065683 for ; Tue, 28 Oct 2008 12:22:38 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from QMTA04.westchester.pa.mail.comcast.net (qmta04.westchester.pa.mail.comcast.net [76.96.62.40]) by mx1.freebsd.org (Postfix) with ESMTP id 8FFAD8FC28 for ; Tue, 28 Oct 2008 12:22:37 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from OMTA04.westchester.pa.mail.comcast.net ([76.96.62.35]) by QMTA04.westchester.pa.mail.comcast.net with comcast id Y9us1a00A0ldTLk54CNYy3; Tue, 28 Oct 2008 12:22:32 +0000 Received: from koitsu.dyndns.org ([69.181.141.110]) by OMTA04.westchester.pa.mail.comcast.net with comcast id YCNX1a00A2P6wsM3QCNXiP; Tue, 28 Oct 2008 12:22:32 +0000 X-Authority-Analysis: v=1.0 c=1 a=QycZ5dHgAAAA:8 a=805D_X94XuiebNnfhCwA:9 a=hRiHZ6EeoBjVE2Z-_dgA:7 a=ljGJ8sdZjAhMmbysZXoRRrsdiz8A:4 a=EoioJ0NPDVgA:10 a=LY0hPdMaydYA:10 Received: by icarus.home.lan (Postfix, from userid 1000) id 49DBDC9419; Tue, 28 Oct 2008 05:22:31 -0700 (PDT) Date: Tue, 28 Oct 2008 05:22:31 -0700 From: Jeremy Chadwick To: Bullet 446 Message-ID: <20081028122231.GB49298@icarus.home.lan> References: <786a1e4f0810280321w7aa8894fnb736fa4c83d3ef5e@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <786a1e4f0810280321w7aa8894fnb736fa4c83d3ef5e@mail.gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) Cc: freebsd-questions@freebsd.org Subject: Re: Zero-Fill format before installation 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: Tue, 28 Oct 2008 12:22:38 -0000 On Tue, Oct 28, 2008 at 10:21:00AM +0000, Bullet 446 wrote: > I have a remote machine with KVM access that I'd like to format and > reinstall FreeBSD 7.0. I've succeded in formatting /dev/ad6 but not the main > drive, /dev/ad4. > Is it possbile to zero-fill format during the installation instead of simply > deleting and recreating partitions? > > I've tried booting into single user mode without any success: > # umount -a > umount: /cdrom: not a file system root directory > umount: /var: not a file system root directory > umount: /usr: not a file system root directory > umount: /tmp: not a file system root directory > # dd if=/dev/zero of=/dev/ad4 > dd: /dev/ad4: Operation not permitted You need to tell GEOM to allow you to overwrite the MBR at the start of the disk. sysctl kern.geom.debugflags=16 then do the dd again. I STRONGLY recommend you add "bs=64k" to that dd statement, or else it's going to take a million years. :-) -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |