From owner-freebsd-questions@FreeBSD.ORG  Wed Jan  7 02:05:23 2009
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
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 B7E2F106564A
	for <freebsd-questions@freebsd.org>;
	Wed,  7 Jan 2009 02:05:23 +0000 (UTC)
	(envelope-from steve@ibctech.ca)
Received: from ibctech.ca (v6.ibctech.ca [IPv6:2607:f118::b6])
	by mx1.freebsd.org (Postfix) with SMTP id 55BF08FC1A
	for <freebsd-questions@freebsd.org>;
	Wed,  7 Jan 2009 02:05:23 +0000 (UTC)
	(envelope-from steve@ibctech.ca)
Received: (qmail 99578 invoked by uid 89); 7 Jan 2009 02:17:44 -0000
Received: from unknown (HELO ?IPv6:2607:f118::5?)
	(steve@ibctech.ca@2607:f118::5)
	by 2607:f118::b6 with ESMTPA; 7 Jan 2009 02:17:44 -0000
Message-ID: <49640DE5.7090308@ibctech.ca>
Date: Tue, 06 Jan 2009 21:05:25 -0500
From: Steve Bertrand <steve@ibctech.ca>
User-Agent: Thunderbird 2.0.0.17 (Windows/20080914)
MIME-Version: 1.0
To: "freebsd-questions@freebsd.org Questions -" <freebsd-questions@freebsd.org>
X-Enigmail-Version: 0.95.7
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Upgrade a USB-stick contained system
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 07 Jan 2009 02:05:24 -0000

Hi everyone,

I run numerous systems (mostly networking gear) from 2GB USB thumb
sticks. These systems do not have hard disks.

To update one of these systems, I'd generally copy the thumb drive
filesystem to a hard disk in another PC, upgrade it, and then transfer
the necessary data back to the USB drive. I'd like to change this approach.

What I'd like to do, is boot the USB drive in another machine that has a
hard drive, and mount any necessary directories for the duration of the
upgrade into the USB drive (such as /usr/src, /usr/ports etc) from the
hard drive. When I'm done, the cruft stays on the physical hard disk,
while the upgraded system on the USB drive is physically replaced back
into the original system.

This is purely a disk-space issue on the USB disk. What I want to know,
is *exactly* what _working_ directories/filesystems are required to
build a new system... working directories that can be dissolved with no
repercussions by using umount.

Steve