From: Andreas Dilger Subject: Re: [ext3] Changes to block device after an ext3 mount point has been remounted readonly Date: Thu, 18 Feb 2010 14:41:45 -0700 Message-ID: <9F53CAF8-B6B4-40EB-89FA-CD6779D17DBE@sun.com> References: Mime-Version: 1.0 Content-Type: text/plain; CHARSET=US-ASCII; delsp=yes; format=flowed Content-Transfer-Encoding: 7BIT Cc: linux-fsdevel@vger.kernel.org, ext4 development To: PiX Return-path: Received: from sca-es-mail-2.Sun.COM ([192.18.43.133]:64908 "EHLO sca-es-mail-2.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755710Ab0BRVmC (ORCPT ); Thu, 18 Feb 2010 16:42:02 -0500 In-reply-to: Sender: linux-ext4-owner@vger.kernel.org List-ID: On 2010-02-18, at 09:45, PiX wrote: > I'm experiencing a strange behavior. After having remounted / to > readonly, I'm doing a sha1sum on /dev/sda1 (which is mounted on /) > Then, I reboot, GRUB starts the kernel with the ro option, when I do a > hash of /dev/sda1 the sum has changed. Are you sure this isn't because e2fsck has been run at boot time and changed e.g. the "last checked" timestamp in the superblock? > This only happen when the rootfs hash been mounted ro, then remounted > rw to make some changes and remounted ro. > On the next reboot the hash will change, but only one time. Next > reboots will not alter the control sum, until of course I remount it > RW. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc.