UNIX for Advanced & Expert Users

i want to determine I/O performance of an
executable,
but iostat dont give correct results because
the disk that i am writing to and reading from,
are not physical disk of the host machine,
instead of these local disks we are using
a network storage.
is there any standard way in unix to get these performance results

The simple answer is to create a test dummy directory on a local disk and run the app against local devices. If iostat is what you want.

Does your box have nfsstat? However iostat & nfsstat tell you about a subsystem(s), not necessarily what one executable is doing.

profiling an app gives you real data for just what the app is doing, and eliminates everybody else. IT may be worth looking at.

If you are using Solaris 10, you can use the iosnoop command that is built with DTrace. Search google for the iosnoop script.
It is able to break down the IO per binary.