Clustering : Installating OpenMPI [HPC = PROGRAMMING]

Installation of OpenMPI

Installation process goes in following steps 

step1 :
check whether there is any c & c++ compilers (gcc,g++,icc,i++), other we have to intall gcc, g++, forton etc..

step2: 
After that only we install openMPI. Download openMPI from the openMPI site.

the file : openmpi-version.tar.bz2

step3:
First create open application directory

# mkdir /apps

# mv openmpi-1.4.3.tar.bz2 /apps

# cd /apps

extarct by # bunzip2 openmpi-1.4.3.tar.baz.2

and then extract 
# tar -xvf openmpi-1.4.3.tar

and then create one temporary directory
# mkdir temp

move the extracted directory to temp

# mv openmpi-1.4.3 temp/

create an empty directory for installation of openMPI

# mkdir openmpi-1.4.3

And go the temp/openmpi-1.4.3/

# cd temp/openmpi-1.4.3/

check list of file in the openmpi-1.4.3

#ls



step4:
Configure the location of installation as

# ./configure –perfix=/apps/openmpi-1.4.3
.
….
…..
After that configuration we make the installation

# make 
.
..
…

After making the files check the make by 

# make check
.
..
…

After that install by make

# make install
.
..
…

Installation is completed .. 

step5:
We run over mpi c programm before that we have to export the path of the installation of openmpi and add LD_LIBRARY_PATH=”/apps/openmpi-1.4.3/lib”

# export PATH=$PATH:”/apps/openmpi-1.4.3/bin” # mpicc, mpi++ .. location

# export LD_LIBRARY_PATH=”/apps/openmpi-1.4.3/lib” # library files location


step6:
Sample open MPI HelloWorld.c

/* Sample MPI "hello World" application in C */



#include <stdio.h>



#include "mpi.h"



int main (int argc, char* argv[])

{

int rank, size;

MPI_Init(&argc, &argv);

MPI_Comm_rank(MPI_COMM_WORLD, &rank); // Procesor id

MPI_Comm_size(MPI_COMM_WORLD, &size); // no.of process running

printf("Hello, World, I am %d of %d\n", rank, size);

MPI_Barrier(MPI_COMM_WORLD);

MPI_Finalize();



return 0;



}


MPICH shell script command to compile and link programs
mpicc
mpiCC
mpif77
mpif90
Command line options:
-help: help on command line options
-compile_info: show commands and options used to compile a program
-link_info: show commands and options used to link a program
-cc : used with mpicc to change the compiler used
-CC: used with mpiCC to change the compiler used
-fc: used with mpif77 to change the compiler used
-f90: used with mpif90 to change the compiler used
Compilation of MPI Program as

C mpicc 
C++ mpic++
forton90 mpif90

and etc

after that we can run output file as

mpirun -np 4 a.out

here np – no of processors