For Read performance you can use sio tool

From: Roscoe P Coltraine [mailto:westlaguy@gmail.com]
Sent: Monday, March 02, 2009 5:24 PM
To: toasters@mathworks.com
Subject: programs to stress/saturate nfs traffic on filer

i want to generate and measure as much load as possible on a unix host via nfs to our filer to capture the max throughput the host
can generate.  we have used iozone but this does not generally saturate the server or the filer.  what i am looking for is something along the lines of
host can sustain X MB/sec throughput and at the same time measure the filers performance/response.

im sure someone has a page with tools on this somewhere