There was a problem in recent kernel (from Sep to Nov) a
program filled up any ffs partition just hangs.  AFAIK, this
is solved at Nov 8 by ffs_balloc.c 1.29 (PR kern/14413).
SMP kernel is using this latest ffs_balloc.c, so I think the
latest kernel should work well.  Please check the version of
your ufs/ffs/ffs_balloc.c.

   On Nov 21, 10:35, Jeff Rizzo wrote:
   > Subject: crash on -current i386 kernel compiled yesterday
   > My /usr filled up, and the machine hung. When I got to the console,
   > it was at a db prompt, and typing "c" got me this:
   > 
   > This is on a compaq DL380 with two processors.  It was running
   > mostly-stable on a 1.5X kernel of a couple months ago until this.
   > (Of course, I never filled up /usr)

-- Kazushi