From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp =?utf-8?q?G=C3=BChring?= Subject: Re: A couple of questions Date: Fri, 17 May 2002 02:45:19 +0200 Message-ID: <200205170048.g4H0mI402129@linux1.futureware.at> References: <20020516214419.GE15774@schmorp.de> <3CE4476E.8070101@namesys.com> Reply-To: p.guehring@futureware.at Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: list-help: list-unsubscribe: list-post: In-Reply-To: <3CE4476E.8070101@namesys.com> List-Id: Content-Type: text/plain; charset="iso-8859-1" To: reiserfs-list@namesys.com -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Dear Hans, > I am a filesystems developer, and I don't know enough to do more than > press y with most fscks. =20 There is one case, in which I know that I have to say no: If the partition = that a fsck tries to correct has a different type than the fsck thinks.=20 (Running e2fsck against a reiserfs partition for example) And those things happens when someone changes harddisks, ... > I think that for the most part, if one is > going to ask the user to help, one needs to provide a real interface, a > filesystem structure editor..... =20 Well, debugfs (ext2) was an approach into that direction, isn't it? Now I stumbled across debugreiserfs, but it lacks interactive mode. > which no FS has ever done.... but > right now we need to get what we have debugged thoroughly. It is on the > list of things I would like to add someday. What I would like to see is a tool to do the following: (And I don't think that I will find a sponsor for that tool :-( After a crash, I make a dd from the crashed partition, into a normal file i= n=20 another partition, that's perhaps on a differnt harddisk. Then I want to run a dumping utility, that tries to restore every bit that = still can be found in the crashed partition, and tries to resemble all the = files in it, and even creating a lost&found directory ... That dumping utility should take an output directory as argument, in which = it=20 recreates the contents. Something like "The Coroners Kit", but more for recovery than for=20 investigation. What is important for that tool: * It must not crash under any circumstances. Even if every bit of the=20 filesystem is currupted, it has to do its work, and try to recover as much = as=20 possible. * It has to assume that every bit of the filesystem can be corrupt, so it h= as=20 to try to semantically verify the bits, pointers, ... * It should try different ways to restore access to lost data, if it stumbl= es=20 across problems in the filesystems. * There must not be any assertions that would not allow the tool to run ove= r=20 the whole partiton, and search everywhere for lost data * It has to be designed to work on files which are dumps from partition bas= ed=20 filesystems. * It should be able to detect and correct common hardware or crash related = problems in the filesystem:=20 * Files that are not statable or accessible, because there only exists an= =20 entry in the directory, but nothing in the reiserfs tree * Transactions that are open * Corrupted directory entries like filenames with special charakters that= =20 can not be used from the system, or rights with undefined bits, ... * ... * It must not change any data on the partition, instead it writes everythin= g=20 to an output directory Many greetings, - --=20 ~ Philipp G=C3=BChring p.guehring@futureware.at -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE85FKjlqQ+F+0wB3oRAlT3AJ9/2t5pDirnnLs/4daKrSKWD2msxQCeIHZx BU+PvfxKKbojRtdnLPerfMY=3D =3DdohB -----END PGP SIGNATURE-----