From owner-freebsd-questions@FreeBSD.ORG Sun Mar 30 12:57:49 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 33E8237B40B for ; Sun, 30 Mar 2003 12:57:49 -0800 (PST) Received: from smtp.comcast.net (smtp-out.comcast.net [24.153.64.109]) by mx1.FreeBSD.org (Postfix) with ESMTP id AAB5543F75 for ; Sun, 30 Mar 2003 12:57:48 -0800 (PST) (envelope-from jshamlet@comcast.net) Received: from whitetower (bgp01561290bgs.gambrl01.md.comcast.net [68.50.33.221]) by mtaout11.icomcast.net (iPlanet Messaging Server 5.2 HotFix 1.12 (built Feb 13 2003)) with ESMTP id <0HCK003A8Y4Q9Z@mtaout11.icomcast.net> for questions@freebsd.org; Sun, 30 Mar 2003 15:55:38 -0500 (EST) Date: Sun, 30 Mar 2003 15:55:38 -0500 (EST) From: "J. Seth Henry" X-X-Sender: jshamlet@whitetower.gambrl01.md.comcast.net To: questions@freebsd.org Message-id: <20030330154319.I73024-100000@whitetower.gambrl01.md.comcast.net> MIME-version: 1.0 Content-type: TEXT/PLAIN; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: /dev on a read-only filesystem? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 Mar 2003 20:57:50 -0000 I have managed, through hook and crook, to get a full 4.7-REL install on a Compaq IA-1 internet appliance. I put a kernel, /bin, /etc, /boot, /dev, /proc, and a partial /sbin on the internal flash memory. During boot, I mount a complete /sbin, /usr and on a microdrive. Since I want to reduce the number of writes to the flash, I linked /tmp, /var, and /root to directories in /usr. So far, so good - the bulk of the write/update activity is now pointed to the microdrive which has no physical write limits. The trick is, if I make / read-only, I run into problems with /dev. During boot, I get numerous error messages - and things don't seem to work quite right. Is there a way to mount / read-only, while maintaining a working /dev? Can /dev be mounted from another filesystem - or, preferably (since the OS is already running) be linked to, say, /usr/dev? If not, how much write activity to the actual, physical volume takes place in /dev. Also, does anything happen on the physical disk with /proc. I don't think it does squat to the physical disk, since a "procfs" filesystem is mounted there, but I want to make sure I don't damage the flash with periodic writes. I would feel best if the internal flash were completely read-only. BTW - if it wasn't clear, the system boots from flash, and them mounts the microdrive. Also, and perhaps unrelated, if I attempt to run getty from the flash, I get an error message about getty spawning too fast - and I can't ever login on the console. This doesn't happen when I launch getty from the microdrive. Odd, but unimportant - as the microdrive is necessary for the system to "run" Thanks, Seth Henry