> > will stop the mount at boot time, it might be barfing on the fsck.
> > Doing one by hand might help.
> 
> Unfortunately, fsck_ext2fs crashes with a "floating point exception"
> when I invoke it.  (Floating point numbers in a file system????)

Probably and integer divide by zero...

> Running gdb on the core file shows:
> 
> Program terminated with signal 8, Floating point exception.
> #0  0x804e7a6 in ?? ()
> #1  0x804dca1 in ?? ()
> #2  0x804abe4 in ?? ()
> #3  0x804ab0c in ?? ()
> #4  0x804825c in ?? ()
> 
> I suppose I need to recompile fsck_ext2fs with debugging info?

Just the symbol table might be enough.
If you have the build tree the OBJ directory is unstripped.

OTOH you'll probably need to debug fsck_ext2fs!
Maybe just mount the filesystem readonly.....

	David

-- 
David Laight: david@l8s.co.uk