freebsd stable - Nov 2004 - help! bad filesystem summary trashes system

Somehow my /usr filesystem ended up being corrupted in such a way that it's 
now recognized as 11 terabytes big and with -11tb free... fsck fails with 
"Cannot alloc 1683933532 bytes for inphead" and when I mount the
corrupted fs
as it is, running pretty much any program completely freezes the system 
(5.3-RELEASE-p1).

What can I do now to make fsck work? I'm amazed something like this can
happen
at all. :-(

-- 
   ,_,   | Michael Nottebrock               | lofi@freebsd.org
 (/^ ^\) | FreeBSD - The Power to Serve     | http://www.freebsd.org
   \u/   | K Desktop Environment on FreeBSD | http://freebsd.kde.org
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On Sunday, 28. November 2004 22:07, Peter Jeremy wrote:
> On 2004-Nov-28 21:44:53 +0100, Michael Nottebrock 
<michaelnottebrock@gmx.net> wrote:
> >Somehow my /usr filesystem ended up being corrupted in such a way that
> > it's now recognized as 11 terabytes big and with -11tb free...
>
> What happened beforehand?  Was this after a clean shutdown, normal crash,
> power failure or what?
I can't really tell. I noticed something was wrong when the system started
to
hang when trying to bring the network interfaces up (I have background 
fsck-enabled, so the bad /usr partition got mounted and as a result, dhclient 
just hangs, like anything else).
> You could try using dumpfs(8) to look at the super block contents.
>
> Have you tried telling fsck to use an alternate super block (-b option)?
I found an alternate superblock at 128, but using it gives the same error.
> If it's just a glitch that's affected the primary super block, this
> should work.  If the in-core data got corrupted and has been written to
> all the superblocks, you might need to play with a filesystem editor.
Can you suggest such an editor (and possibly give some hints what exactly to 
do with it)? 

-- 
   ,_,   | Michael Nottebrock               | lofi@freebsd.org
 (/^ ^\) | FreeBSD - The Power to Serve     | http://www.freebsd.org
   \u/   | K Desktop Environment on FreeBSD | http://freebsd.kde.org
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