From mboxrd@z Thu Jan 1 00:00:00 1970 From: Theodore Tso Subject: Re: EXT4 partition changes every time it's mounted. (How to stop this?) Date: Sun, 22 May 2011 07:47:49 -0400 Message-ID: References: <476510.14310.qm@web125206.mail.ne1.yahoo.com> Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Cc: "linux-ext4@vger.kernel.org" To: Lee Davis Return-path: Received: from DMZ-MAILSEC-SCANNER-2.MIT.EDU ([18.9.25.13]:57022 "EHLO dmz-mailsec-scanner-2.mit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754032Ab1EVLrw convert rfc822-to-8bit (ORCPT ); Sun, 22 May 2011 07:47:52 -0400 In-Reply-To: <476510.14310.qm@web125206.mail.ne1.yahoo.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On May 21, 2011, at 3:45 PM, Lee Davis wrote: > I'm setting up a Linux system with full disk encryption. I've written a script (to run on every boot) which will verify that neither the MBR or /boot partition (ext4) has been modified. > > Problem is that every time I boot up the system, my /boot partition hashes differently. > > I'm guessing there is something behind the scenes which is changed/updated each time the filesystem is mounted? If so, can it be disabled? Yes, there is a last mounted time in the superblock. If you mount the file system read-only, then not only will that field not be changed, but you can guarantee that nothing else will change... -- Ted