From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751108AbWDFG6g (ORCPT ); Thu, 6 Apr 2006 02:58:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751135AbWDFG6g (ORCPT ); Thu, 6 Apr 2006 02:58:36 -0400 Received: from lug-owl.de ([195.71.106.12]:56765 "EHLO lug-owl.de") by vger.kernel.org with ESMTP id S1751108AbWDFG6g (ORCPT ); Thu, 6 Apr 2006 02:58:36 -0400 Date: Thu, 6 Apr 2006 08:58:32 +0200 From: Jan-Benedict Glaw To: Sumit Narayan Cc: linux-kernel , ext3-users@redhat.com Subject: Re: deleting partition does not effect superblock? Message-ID: <20060406065832.GK13324@lug-owl.de> Mail-Followup-To: Sumit Narayan , linux-kernel , ext3-users@redhat.com References: <1458d9610604052337p2cafa6c8j78fc6da8c5f8be1a@mail.gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="GmiNL4+5WUWrod5m" Content-Disposition: inline In-Reply-To: <1458d9610604052337p2cafa6c8j78fc6da8c5f8be1a@mail.gmail.com> X-Operating-System: Linux mail 2.6.12.3lug-owl X-gpg-fingerprint: 250D 3BCF 7127 0D8C A444 A961 1DBD 5E75 8399 E1BB X-gpg-key: wwwkeys.de.pgp.net X-Echelon-Enable: howto poison arsenous mail psychological biological nuclear warfare test the bombastical terror of flooding the spy listeners explosion sex drugs and rock'n'roll X-TKUeV: howto poison arsenous mail psychological biological nuclear warfare test the bombastical terror of flooding the spy listeners explosion sex drugs and rock'n'roll User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --GmiNL4+5WUWrod5m Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, 2006-04-06 14:37:33 +0800, Sumit Narayan wro= te: > Shouldn't the superblock be changed/deleted once the partition is > deleted? I tried a reboot, but the output remained the same. No, everything you see is "works as expected." A partition is only a container (as well as "disks", "volume groups", "RAID arrays", "logical volumes", "image files" etc. are.) Whenever you destroy such a container, its contents isn't modified (or deleted) or otherwise modified. So it's perfectly okay to delete such a container (eg. remove start and end from the partition table) and recreate it at some time later (by adding those values back to the partition table.) As long as the new container starts at the same location, a filesystem driver will be able to find the old information. If you start a block later, it won't find it's superblocks. Finally, you have several choices how to defeat getting back old data. Most probably, you'd just zero it out before deleting the partition with something like: # cat /dev/zero > /dev/hda3 (of course with the correct device name!) MfG, JBG --=20 Jan-Benedict Glaw jbglaw@lug-owl.de . +49-172-7608481 = _ O _ "Eine Freie Meinung in einem Freien Kopf | Gegen Zensur | Gegen Krieg = _ _ O f=C3=BCr einen Freien Staat voll Freier B=C3=BCrger" | im Internet! | i= m Irak! O O O ret =3D do_actions((curr | FREE_SPEECH) & ~(NEW_COPYRIGHT_LAW | DRM | TCPA)= ); --GmiNL4+5WUWrod5m Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQFENLwYHb1edYOZ4bsRAqmpAJ9xEHG5uBpoig6R0u8koosGzeLcigCfRQCq fBlGG16bfZSbwbI9B6HEtOk= =vkZ4 -----END PGP SIGNATURE----- --GmiNL4+5WUWrod5m--