buffer cache size

[Michael O'Dell]

Largely speaking, if you are running 4.0 or later on your server, there
ain't no buffer cache, per se, any more!!  All of memory is simply a cache
for everything in virtual space, including files being vended by NFS.  In
4.0, buf headers are still used for outstanding I/O requests, but after
the I/O is done, the pages are in the general virtual memory cache.

SO, there is no knob to turn...

	-Mike