The error you're seeing is probably "panic(vbwrite)".
This is a kernel panic error which occurred in the I/O buffer routines. The
I/O buffer routines take care of reading/writing and freeing buffers within the
UNIX kernel. In this case the kernel thinks the size of the available buffers
are smaller than the amount of data that needs to be written out. In other
words, you can't write out what you don't have. This is a very serious error,
which under normal circumstances should never occur.
The first thing to resolve the problem is to try a "kconfig -v -a /UNIX >
kernel.conf" and have the output checked by an expert.
Let the same person look at a "module_dump /unix".