From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manuel Krause Subject: Re: A couple of questions Date: Fri, 17 May 2002 03:06:41 +0200 Message-ID: <3CE457A1.6040507@netscape.net> References: <20020516214419.GE15774@schmorp.de> <3CE4476E.8070101@namesys.com> <200205170048.g4H0mI402129@linux1.futureware.at> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: list-help: list-unsubscribe: list-post: List-Id: Content-Type: text/plain; charset="iso-8859-9"; format="flowed" To: reiserfs-list On 05/17/2002 02:45 AM, Philipp G=FChring wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 >=20 > Dear Hans, >=20 >=20 >>I am a filesystems developer, and I don't know enough to do more than >>press y with most fscks. =20 >> >=20 > There is one case, in which I know that I have to say no: If the partition= =20 > that a fsck tries to correct has a different type than the fsck thinks.=20 > (Running e2fsck against a reiserfs partition for example) >=20 > And those things happens when someone changes harddisks, ... >=20 >=20 >>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 >> >=20 > Well, debugfs (ext2) was an approach into that direction, isn't it? > Now I stumbled across debugreiserfs, but it lacks interactive mode. >=20 >=20 >>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. >> >=20 > 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 :-( >=20 > After a crash, I make a dd from the crashed partition, into a normal file=20= in=20 > another partition, that's perhaps on a differnt harddisk. >=20 > Then I want to run a dumping utility, that tries to restore every bit that= =20 > still can be found in the crashed partition, and tries to resemble all the= =20 > files in it, and even creating a lost&found directory ... >=20 > That dumping utility should take an output directory as argument, in which= it=20 > recreates the contents. It should take a FILE of the SAME size of the original partition as=20 output. So the utility or user may dd it back safely. >=20 > Something like "The Coroners Kit", but more for rec2overy than for=20 > investigation. >=20 > 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=20= has=20 > to try to semantically verify the bits, pointers, ... > * It should try different ways to restore access to lost data, if it stumb= les=20 > across problems in the filesystems. > * There must not be any assertions that would not allow the tool to run ov= er=20 > the whole partiton, and search everywhere for lost data > * It has to be designed to work on files which are dumps from partition ba= sed=20 > filesystems. > * It should be able to detect and correct common hardware or crash related= =20 > problems in the filesystem:=20 > * Files that are not statable or accessible, because there only exists a= n=20 > entry in the directory, but nothing in the reiserfs tree > * Transactions that are open > * Corrupted directory entries like filenames with special charakters tha= t=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 everythi= ng=20 > to an output directory ...FILE, that is able to be checked manually via loop-mount to see the=20 difference... Philipp is very right on his needs. We all are interestedm=20 I assume. >=20 > 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 >=20 > iD8DBQE85FKjlqQ+F+0wB3oRAlT3AJ9/2t5pDirnnLs/4daKrSKWD2msxQCeIHZx > BU+PvfxKKbojRtdnLPerfMY=3D > =3DdohB > -----END PGP SIGNATURE----- >=20 Best wishes, Manuel