> > d) A bug somewhere else entirely is trashing filesystem data structures.
 > 
 > This is probably it.  I ran into a repeatable problem that would cause
 > my alphas to go belly-up in ffs_clusteracct, and only fixed it a week
 > or two ago.  This bug was fixed in Lite2, but Lite2 hasn't been
 > integrated into NetBSD yet.

Thanks Chris! I've applied this, and we'll see if it helps Gord.
To Gord: I've put a couple of new kernels on ftp.unit.no, try
	/pub/NetBSD/arch/pmax/binary-1.1-alpha3/rz1netbsd.dbg
first.  If it crashes in the same place it's probably going to say
8010c208+a64 (or maybe: ffs_alloccgblk+a64, if it understand those
symbols).

  -  Arne H. J.