From owner-freebsd-fs@FreeBSD.ORG Tue Aug 30 14:50:30 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D8D19106566B for ; Tue, 30 Aug 2011 14:50:30 +0000 (UTC) (envelope-from ee@athyriogames.com) Received: from madonna.sslcatacombnetworking.com (madonna.sslcatacombnetworking.com [174.133.19.130]) by mx1.freebsd.org (Postfix) with ESMTP id B713D8FC19 for ; Tue, 30 Aug 2011 14:50:30 +0000 (UTC) Received: from c-98-206-215-156.hsd1.in.comcast.net ([98.206.215.156] helo=laptopv) by madonna.sslcatacombnetworking.com with esmtpa (Exim 4.69) (envelope-from ) id 1QyPTr-0004c9-Mt for freebsd-fs@freebsd.org; Tue, 30 Aug 2011 09:39:59 -0500 From: "Engineering" To: References: <01c801cc667f$f99eb7b0$ecdc2710$@com> In-Reply-To: <01c801cc667f$f99eb7b0$ecdc2710$@com> Date: Tue, 30 Aug 2011 09:49:41 -0500 Message-ID: <020d01cc6724$0f0410b0$2d0c3210$@com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: Acxmf/bkxg/WNgMwTaWJDIhaLpbyEAAo4bzQ Content-Language: en-us X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - madonna.sslcatacombnetworking.com X-AntiAbuse: Original Domain - freebsd.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - athyriogames.com Subject: RE: Read-only disk problem X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Aug 2011 14:50:30 -0000 Hi, I've attached some more info. Doing a fsdump shows the following changes over reboot magic 19540119 (UFS2) time Tue Aug 30 03:08:04 2011 ... cg 1: magic 90255 tell 4b1c000 time Tue Aug 30 03:08:04 2011 Changes to magic 19540119 (UFS2) time Tue Aug 30 03:13:14 2011 ... cg 1: magic 90255 tell 4b1c000 time Tue Aug 30 03:13:14 2011 Sam -----Original Message----- From: owner-freebsd-fs@freebsd.org [mailto:owner-freebsd-fs@freebsd.org] On Behalf Of Engineering Sent: Monday, August 29, 2011 2:15 PM To: freebsd-fs@freebsd.org Subject: Read-only disk problem Please let me know if this is the wrong place to ask. I am working on an embedded system using FreeBSD 7.2, bootinf and running off of flash memory. In order to not burn out the flash, I use the 'diskless' scripts and mount the flash read-only. I have used this configuration successfully in the past. I've recently added a utility to check for disk corruption, basically checksumming the / and /usr partitions. Since they are both read-only, I thought this would work. What I have discovered is that something in the partition is changing between boots. I dd'd the flash over a couple of boots, and compared the binaries to see what was changing. It is a small amount of data, spread across the disk, in an interval that looks very similar to the interval of the 'superblocks' Is there any data that is written to the disk at boot or mount time, and if so, is there a way to prevent it? Thanks Sam _______________________________________________ freebsd-fs@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-fs To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org"