From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932097AbXDIKOo (ORCPT ); Mon, 9 Apr 2007 06:14:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932128AbXDIKOn (ORCPT ); Mon, 9 Apr 2007 06:14:43 -0400 Received: from mail.clusterfs.com ([206.168.112.78]:54997 "EHLO mail.clusterfs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932097AbXDIKOm (ORCPT ); Mon, 9 Apr 2007 06:14:42 -0400 Date: Mon, 9 Apr 2007 04:14:40 -0600 From: Andreas Dilger To: Eric Sandeen Cc: Samuel Thibault , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Add a norecovery option to ext3/4? Message-ID: <20070409101440.GM5967@schatzie.adilger.int> Mail-Followup-To: Eric Sandeen , Samuel Thibault , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org References: <20070409000556.GA13980@implementation> <4619B202.3050601@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4619B202.3050601@redhat.com> User-Agent: Mutt/1.4.1i X-GPG-Key: 1024D/0D35BED6 X-GPG-Fingerprint: 7A37 5D79 BF1B CECA D44F 8A29 A488 39F5 0D35 BED6 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Apr 08, 2007 22:24 -0500, Eric Sandeen wrote: > Samuel Thibault wrote: > >Distribution installers usually try to probe OSes for building a suited > >grub menu. Unfortunately, mounting an ext3 partition, even in read-only > >mode, does perform some operations on the filesystem (log recovery). > >This is not a good idea since it may silently garbage data. > > Can you elaborate? Under what circumstances is log replay going to harm > data? Do you mean that the installer mounts partitions, looking for > what OS is installed? How is that harmful? If that disk was actually in use on another system but just exported via a SAN to this node you've potentially corrupted the filesystem. It's a bad idea to just go ahead and mount filesystems that you aren't told to mount. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc.