increasing number of buffers in BSD4.4

[Eno Thereska]

Hi,

In McKusick's book "The design and Implementation of the 4.4BSD 
Operating system", in the "Buffer Management subsection
of the I/O system overview, there is a a sentence that says
"...depending on available memory, a system is configured with from
100 to 1000 buffers.." referring to the number of struct buf* in the
integrated VM/IO buffer cache.

I have plenty of RAM in my computer, but it seems like there are always
1000 buffers configured (empirical observation, if I try to allocate
one more after that the system freezes). How do I increase the nubmer of
buffers? More consicely, how do I allocate more memory to the buffer 
management subsystem?

Thanks
Eno