From owner-freebsd-questions@FreeBSD.ORG  Thu Jul 30 19:05:02 2009
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 771F0106566C
	for <freebsd-questions@freebsd.org>;
	Thu, 30 Jul 2009 19:05:02 +0000 (UTC)
	(envelope-from rsmith@xs4all.nl)
Received: from smtp-vbr10.xs4all.nl (smtp-vbr10.xs4all.nl [194.109.24.30])
	by mx1.freebsd.org (Postfix) with ESMTP id E63708FC12
	for <freebsd-questions@freebsd.org>;
	Thu, 30 Jul 2009 19:05:01 +0000 (UTC)
	(envelope-from rsmith@xs4all.nl)
Received: from slackbox.xs4all.nl (slackbox.xs4all.nl [213.84.242.160])
	by smtp-vbr10.xs4all.nl (8.13.8/8.13.8) with ESMTP id n6UJ4xUC006873;
	Thu, 30 Jul 2009 21:04:59 +0200 (CEST)
	(envelope-from rsmith@xs4all.nl)
Received: by slackbox.xs4all.nl (Postfix, from userid 1001)
	id 2CE52BAAE; Thu, 30 Jul 2009 21:04:59 +0200 (CEST)
Date: Thu, 30 Jul 2009 21:04:59 +0200
From: Roland Smith <rsmith@xs4all.nl>
To: PJ <af.gourmet@videotron.ca>
Message-ID: <20090730190458.GA36265@slackbox.xs4all.nl>
References: <4A71DB2A.4040401@videotron.ca>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha1;
	protocol="application/pgp-signature"; boundary="mYCpIKhGyMATD0i+"
Content-Disposition: inline
In-Reply-To: <4A71DB2A.4040401@videotron.ca>
X-GPG-Fingerprint: 1A2B 477F 9970 BA3C 2914  B7CE 1277 EFB0 C321 A725
X-GPG-Key: http://www.xs4all.nl/~rsmith/pubkey.txt
X-GPG-Notice: If this message is not signed, don't assume I sent it!
User-Agent: Mutt/1.5.20 (2009-06-14)
X-Virus-Scanned: by XS4ALL Virus Scanner
Cc: freebsd-questions@freebsd.org
Subject: Re: how to boot or access problem file system
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 30 Jul 2009 19:05:02 -0000


--mYCpIKhGyMATD0i+
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Thu, Jul 30, 2009 at 01:40:58PM -0400, PJ wrote:
> What can be done to access a file system that seems to have the boot
> sector screwed up?

Do you mean the filesystem's superblock? Or the slice table (partitions
in PC parlance) or the freebsd partitions (disk labels)? Because the
boot sector is not part of any filesystem.=20

The best way to try repairs is to make a complete copy of the partition
with dd(1), and experiment on the copy. That way you cannot further screw
up the original!

To check a UFS filesystem, use fsck_ffs(8). First, try if the preen
option '-p' is sufficient to fix the filesystem. If the superblock is
corrupt, try using the -b option to specify an alternate superblock. See
the manual page.

> The /usr files should be ok but how to access?

Use fsck_ffs to try and repair the filesystem.

> I get errors that the file system is full and I have no idea of how to
> deal with the boot up - the help message is no help!
> Boot says it cannot find a kernel... surely there must be some kind of
> recovery process even if nothing has been backed up. Surely FreeBSD must
> be have something that functions like certain software does on MS ?

Maybe the sleuth kit (sysutils/sleuthkit) can help you recover files.=20

> I don't have a problem with irrecoverable files, I would just finally
> understand how things work and what can be done on FBSD.

Make regular backups. Especially before big upgrades.

Roland
--=20
R.F.Smith                                   http://www.xs4all.nl/~rsmith/
[plain text _non-HTML_ PGP/GnuPG encrypted/signed email much appreciated]
pgp: 1A2B 477F 9970 BA3C 2914  B7CE 1277 EFB0 C321 A725 (KeyID: C321A725)

--mYCpIKhGyMATD0i+
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.12 (FreeBSD)

iEYEARECAAYFAkpx7toACgkQEnfvsMMhpyXrpwCfYBS/yv3xZ2G23roo8uWczVWs
H94Amwefm4R7s/7JUWT5kNai/xWOH9QY
=CWMj
-----END PGP SIGNATURE-----

--mYCpIKhGyMATD0i+--