WHERE_I_LEFT_OFF.txt

Did:
To Do:
1. I have an interactive allocation on, 3 tasks, 2 cpus-per-task, 2 nodes 
   himem[01-02]

    Figure out why :
    a) on qmaster01

    b) srun -n2 --mpi=openmpi --jobid=2431623 ./a.out
       --> Spawns two mpi-tasks (both taskID=0), one on each node

    c) srun --mpi=openmpi --jobid=2431623 mpirun -n 2 ./a.out
       --> Spawns 4 mpi-tasks. It seems like it is the equivalent to running
           mpirun -n 2 on each node

   
    This works : 
    a) Allocate interactive session : 
            module load openmpi-1.8/gcc-4.9.2
            salloc --ntasks=2 --nodes=2     # Gets two nodes with 1 core each
                (within new shell...)
            mpirun -np 2 ./a.out            # Works as expected.
            mpirun -np 4 ./a.out            # Fails b/c not enough cores in tasks
        
    b) Allocate interactive session : 
            module load openmpi-1.8/gcc-4.9.2
            salloc --ntasks=2 --nodes=2 --nodelist=node[14,15] --cpus-per-task=2
                (within new shell...)
            mpirun -np 2 ./a.out            # Works as expected
            mpirun -np 3 ./a.out            # Fails, probably b/c need ntasks == np