hangs in nbufkv

Hello!

While investigating the server's hanging, I noticed some processes in 
the `nbufkv' state (even a graceful reboot becomes impossible: "some 
processes would not die..."). Quick search brought up links like:

    http://lists.freebsd.org/pipermail/freebsd-current/2003-June/004702.html
    
http://docs.freebsd.org/cgi/getmsg.cgi?fetch=56559+0+archive/1999/freebsd-current/19991031.freebsd-current
    
http://docs.freebsd.org/cgi/getmsg.cgi?fetch=406042+0+archive/1999/freebsd-current/19991031.freebsd-current

One of our file systems here does, indeed, use large block size (64K, I 
think, not sure, how to verify it) -- it is used for storing large 
database dumps. Are the bugs, Bruce and Matt are talking about, supposed 
to be gone by now (in which case, I can provide more debugging info), or 
does this remain a "known problem" and I should simply adopt the 
workaround suggested by Bruce in the first link above -- increase 
BKVASIZE? Should I also merge the patch posted by Bruce in the last of 
the links above, or are there good reasons, it is not in the official tree?

In the former case, what would anyone need to know to help fix this 
problem(s)?

In the latter -- what is a good BKVASIZE value for an amd64 opteron with 
2Gb of memory, intended, primarily, to keep database archives online and 
handy?

Thanks!

    -mi