Linux Environment Modules or Conda Environment

Question

I looked for the difference between the Linux Environment Modules or Conda Environment, but I am not clear how are these different. Basically, I want to install OpenMPI and Mpich both in my Ubuntu, but they share the several compiler wrappers. To be on safe side, I want to isolate them, so what should I use - Modules or Conda Environment or any other alternative?

Also, if I use Conda Environment, can I limit the compiled software binary to the environment? I am surprised that I have installed some software in the base environment but I am able to access is from another environment.

Answer 1

Environment Modules is designed to enable users with software not available in the default environment. In your situation, you can install both OpenMPI and Mpich in isolated paths, then with modulefiles users can enable the MPI flavor of their choice.

This is what is provided by default when you install openmpi and mpich on a Fedora system for instance:

$ module show mpi/mpich-x86_64 
-------------------------------------------------------------------
/etc/modulefiles/mpi/mpich-x86_64:

conflict        mpi
setenv          MPI_BIN /usr/lib64/mpich/bin
setenv          MPI_SYSCONFIG   /etc/mpich-x86_64
setenv          MPI_FORTRAN_MOD_DIR     /usr/lib64/gfortran/modules/mpich
setenv          MPI_INCLUDE     /usr/include/mpich-x86_64
setenv          MPI_LIB /usr/lib64/mpich/lib
setenv          MPI_MAN /usr/share/man/mpich-x86_64
setenv          MPI_PYTHON_SITEARCH     /usr/lib64/python2.7/site-packages/mpich
setenv          MPI_PYTHON2_SITEARCH    /usr/lib64/python2.7/site-packages/mpich
setenv          MPI_PYTHON3_SITEARCH    /usr/lib64/python3.6/site-packages/mpich
setenv          MPI_COMPILER    mpich-x86_64
setenv          MPI_SUFFIX      _mpich
setenv          MPI_HOME        /usr/lib64/mpich
prepend-path    PATH /usr/lib64/mpich/bin
prepend-path    LD_LIBRARY_PATH /usr/lib64/mpich/lib
prepend-path    MANPATH /usr/share/man/mpich-x86_64
prepend-path    PKG_CONFIG_PATH /usr/lib64/mpich/lib/pkgconfig
-------------------------------------------------------------------
$ module show mpi/openmpi-x86_64 
-------------------------------------------------------------------
/usr/share/modulefiles/mpi/openmpi-x86_64:

conflict        mpi
prepend-path    PATH /usr/lib64/openmpi/bin
prepend-path    LD_LIBRARY_PATH /usr/lib64/openmpi/lib
prepend-path    PKG_CONFIG_PATH /usr/lib64/openmpi/lib/pkgconfig
prepend-path    MANPATH /usr/share/man/openmpi-x86_64
setenv          MPI_BIN /usr/lib64/openmpi/bin
setenv          MPI_SYSCONFIG   /etc/openmpi-x86_64
setenv          MPI_FORTRAN_MOD_DIR     /usr/lib64/gfortran/modules/openmpi
setenv          MPI_INCLUDE     /usr/include/openmpi-x86_64
setenv          MPI_LIB /usr/lib64/openmpi/lib
setenv          MPI_MAN /usr/share/man/openmpi-x86_64
setenv          MPI_PYTHON_SITEARCH     /usr/lib64/python2.7/site-packages/openmpi
setenv          MPI_PYTHON2_SITEARCH    /usr/lib64/python2.7/site-packages/openmpi
setenv          MPI_PYTHON3_SITEARCH    /usr/lib64/python3.6/site-packages/openmpi
setenv          MPI_COMPILER    openmpi-x86_64
setenv          MPI_SUFFIX      _openmpi
setenv          MPI_HOME        /usr/lib64/openmpi
-------------------------------------------------------------------