From owner-freebsd-current@FreeBSD.ORG Wed Jun 30 13:31:25 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C909A16A4CE for ; Wed, 30 Jun 2004 13:31:25 +0000 (GMT) Received: from gromit.dlib.vt.edu (gromit.dlib.vt.edu [128.173.49.29]) by mx1.FreeBSD.org (Postfix) with ESMTP id 5735843D48 for ; Wed, 30 Jun 2004 13:31:25 +0000 (GMT) (envelope-from paul@gromit.dlib.vt.edu) Received: from hawkwind.Chelsea-Ct.Org (pool-151-199-92-118.roa.east.verizon.net [151.199.92.118]) by gromit.dlib.vt.edu (8.12.11/8.12.11) with ESMTP id i5UDUVIR067202 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 30 Jun 2004 09:30:33 -0400 (EDT) (envelope-from paul@gromit.dlib.vt.edu) Received: from [192.168.1.25] (zappa [192.168.1.25])i5UDUIiS011118; Wed, 30 Jun 2004 09:30:19 -0400 (EDT) From: Paul Mather To: "Thyer, Matthew" In-Reply-To: References: Content-Type: text/plain Message-Id: <1088602216.84518.15.camel@zappa.Chelsea-Ct.Org> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Wed, 30 Jun 2004 09:30:18 -0400 Content-Transfer-Encoding: 7bit cc: freebsd-current@freebsd.org cc: Paul Seniura cc: Carl Makin Subject: RE: Q's about IBM TSM (was Re: HEADSUP: ibcs2 and svr4 comp at headed for history) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Jun 2004 13:31:25 -0000 On Wed, 2004-06-30 at 00:45, Thyer, Matthew wrote: > I would love to have this automatic generation/maintenance of /compat/linux/etc/mtab. > > This would help me greatly for backup of systems using Linux backup software. > > Currently the software (HP OpenView DataProtector) will fail to backup the system if the file does not contain lines regarding the file systems I want to backup. > > Ideally this would need some kernel support to handle updating of the file whenever file systems are manually mounted and unmounted. Remember that Linux's etc/mtab file is to record what is currently mounted. A simple translation of FreeBSD's /etc/fstab at module load time or system boot time is not really adequate. In my case (using Tivoli TSM to back up snapshots via the TSM scheduler) I use the "preschedulecmd" script hooks to update the mtab file to reflect the current mounts (and make the snapshots). If your backup client has pre- and post-backup scripting support, you could take advantage of this approach to modify mtab appropriately. Another alternative would be to make a wrapper script around your backup client that updated mtab and then called the real backup client. Unless your mounts are very volatile, even a cron job that updated mtab before the anticipated backup window (or a manual script execution that did the same prior to a manual backup) would suffice in the absence of any automagic kernel support. Also, it's unclear what the correct semantics for an automatic kernel-based translation would be. In the case of Tivoli TSM, you have to lie and say your ufs filesystems are ext2, because TSM doesn't understand or recognise ufs but it does ext2. It's not clear whether such a lie is valid for all programs run under Linux emulation. However, performing a "straight" translation, preserving the true filesystem type, would actually *prevent* TSM from working properly under FreeBSD... Cheers, Paul. -- e-mail: paul@gromit.dlib.vt.edu "Without music to decorate it, time is just a bunch of boring production deadlines or dates by which bills must be paid." --- Frank Vincent Zappa