From owner-freebsd-questions@FreeBSD.ORG Sat May 2 22:52:50 2015 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 772BBE7C for ; Sat, 2 May 2015 22:52:50 +0000 (UTC) Received: from fly.hiwaay.net (fly.hiwaay.net [216.180.54.1]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 3BC471119 for ; Sat, 2 May 2015 22:52:49 +0000 (UTC) Received: from kabini1.local (rbn1-216-180-19-39.adsl.hiwaay.net [216.180.19.39]) (authenticated bits=0) by fly.hiwaay.net (8.13.8/8.13.8/fly) with ESMTP id t42MqlFZ006245 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Sat, 2 May 2015 17:52:48 -0500 Message-ID: <5545553F.50602@hiwaay.net> Date: Sat, 02 May 2015 17:59:02 -0453 From: "William A. Mahaffey III" User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: freebsd-questions@freebsd.org Subject: Re: How to restore a USB drive converted to bootable References: <5543FAA3.7050907@hiwaay.net> <441tiz3wrx.fsf@lowell-desk.lan> <5544DBA2.1030102@hiwaay.net> <20150502233854.c80bc5ae.freebsd@edvax.de> <55454CDA.3020209@hiwaay.net> <20150503002420.fdcc9310.freebsd@edvax.de> In-Reply-To: <20150503002420.fdcc9310.freebsd@edvax.de> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 May 2015 22:52:50 -0000 On 05/02/15 17:30, Polytropon wrote: > On Sat, 02 May 2015 17:23:13 -0453, William A. Mahaffey III wrote: >> On 05/02/15 16:45, Polytropon wrote: >>> On Sat, 02 May 2015 09:20:09 -0453, William A. Mahaffey III wrote: >>>> On 05/02/15 09:06, Lowell Gilbert wrote: >>>>> "William A. Mahaffey III" writes: >>>>> >>>>>> I am about to do some OS installs (NetBSD & OpenBSD, as it happens) on >>>>>> boxen under construction. I would also like to use UBCD on a flash >>>>>> drive to memcheck those boxen prior to installation. If I prep a USB >>>>>> thumb drive as either a bootable UBCD drive or an over-the-WWW >>>>>> installer, I wipe out the drive for its original use. Is there a way >>>>>> to restore the drive back to its original functionality if I wanted to >>>>> Is "wipe the drive and reformat" what you need to hear, or do you have >>>>> more requirements that you haven't made clear? >>>>> >>>> Wipe & reformat, preferably from CLI under FBSD 9.3R-p13 for >>>> convenience, is what I'm after. Clearly creating a bootable UBCD or >>>> installer will wipe out whatever was >>>> there before, so I just want to get back to 'virgin' USB drive. >>> In that case, the command >>> >>> # dd if=/dev/zero of=/dev/da0 bs=1m count=1 >>> >>> should be fine. If there is any offending GPT metadata located >>> at the end of the USB drive, estimate the size and also erase >>> the last few MBs (use skip= to do so). There is no need to >>> actually zero out the _whole_ drive. >> *Aaaaaaaaaaaaaaahhhhh*, I wasn't sure about that (zero the whole drive), >> thanks :-) .... > There are only few significant "data zones" on the USB drive. > The boot sector and partition table are located at the beginning, > and _maybe_ GPT metadata at the end. Removing both makes the > remaining bits and bytes practically useless (except when you > take it to forensics, but you don't want to recover things > anyway, so the result should work for you). > > However, if you want a USB drive "new" (as in "I just bought it > from the shop, it's fresh out of the package!"), then you have > to write a MSDOS (FAT) file system, install some crapware, some > ridiculous "drivers", and "value added" software, maybe with > some spying tools, malware, nagware, and non-working "encryption" > tools. Add several partitions and make them smaller than the > real size of the drive. And add a "Facebook" link. :-) > > > I was thinking of dd-ing the 1st MB or 2 off into a file, then restoring from that file when done, that would skip all the extra features you mention ;-). Would 1 or 2 MB be enough to get all of the FS info ? I wasn't aware you didn't have to zero everything out, that simplifies things a fair bit .... -- William A. Mahaffey III ---------------------------------------------------------------------- "The M1 Garand is without doubt the finest implement of war ever devised by man." -- Gen. George S. Patton Jr.