Does anyone know the magic incantation (or is it even possible) to
produce a 256MB buffer cache under NetBSD/i386 1.3.2?  I've made a few
attempts thus far:

  - A kernel configured for 256MB of buffer cache won't even boot.  I
    assume this is because the KVA space is being exhausted by the
    cache.

  - Kernels with 128MB of buffer cache are unstable and often corrupt
    files.  Could this be caused by an insufficient number of buffer
    headers (NBUF)?  Attempts at tweaking NBUF (as described in the
    mailing list archives) haven't yielded better results.

If 256MB requires altering the KVA size and altering the KVA size is
difficult, I'd settle for a reliable 128MB cache.  Does anyone have a
working configuration they could share?

Alex