Running MPICH code on a subset of the cluster

The cluster has been split in to 4 subsets using 4 mach files named mach1, mach2, mach3 and mach4. Each mach file has a list of processors that can be used as a given subset. Here is an example of how to run the dist_fft_test on a subset of the apple cluster:

• Log onto master node of cluster

• Set Paths and compile program (see previous section for details)

• From the master node, ssh to a node in the subset you wish to work with
  ssh node005.cluster.private
  

• The home directories are available on all the nodes. Move to the directory containing your code:
  cd /common/Users/astewart/diffmic/c/dist_fft
  

• Run the program as before, using the mach file appropriate to your subset of processors to be used:
  mpirun -np 2 -machinefile mach2 dist_fft_test 12