openmpi/INSTALL

Execute the following instructions to install the Open MPI system from within the directory at the top of the tree:

./autogen.sh (if this fails read the HACKING file)
./configure --prefix=/where/to/install
make install

To run an MPI program:

mpicc your-code.c

In order to run the program, you need to set some envs (use export for bash etc)

setenv OMPI_MCA_oob_cofs_dir /tmp/cofs
setenv OMPI_MCA_pcm_cofs_cellid 1
setenv OMPI_MCA_pcm_cofs_jobid 1

Then if you need to run say N nodes you need to set:
setenv OMPI_MCA_pcm_cofs_num_procs N

Then in the shell for each you would set

setenv OMPI_MCA_pcm_cofs_procid MYRANK

where MYRANK is 0 in one, 1 in the next etc

Or - you can use the mpirun shell script which sets these for you...

This is the world's greatest MPI, version 10.0a1r975.