Environment Variables and Modules

The operating system on obsidian is RHEL 7. To change the environment variables loaded upon login, users may modify .bash_profile or .csh_profile.

Obsidian uses modules because it allows the users to choose what software or which version of the software they wish to use, without worrying about the correct environment variables and library links. Currently, the following modules are available on obsidian:
mvapich2-2.1/gcc   openmpi-1.8/gcc   mpich/gcc   openmpi-1.6/gcc   xmgr/4.1.2

Load Modules

To load a module, type: module load module_name. For example, if you compile and run MPI program in C using InfiniBand interconnect, you need to do the following:

module load mvapich2-2.1/gcc
mpicc source_code.c
mpirun -np nprocs -machinefile $PBS_NODEFILE executable

Available Compilers

Currently, only gcc compiler is installed at system level. If you have a floating license compiler that you would like to install at the system level, please contact OIT help desk (X2910) and ask that you request to be assigned to "Research Computing" queue.

For MPI programs, you may load appropriate MPI compiler using module load. If you need to change to a different module, in some occasions you may need to unload the previously loaded module first.