Did you request an allocation from PCM? If not, then PCM will block you from arbitrarily launching jobs on non-allocated nodes. Print out your environment and look for any envars from PCM and/or LSF (e.g., LSB_JOBID).

I don't know what you mean about "no OMPI application is yet integrated with LSF" - an application would never be integrated with LSF. However, OMPI will configure itself to use LSF as its launcher if it detects the presence of LSF on the system. When that happens, you no longer need to supply a machinefile as OMPI will automatically pickup the list of allocated nodes.

On Apr 4, 2011, at 9:31 PM, Ahsan Ali wrote:

Dear John Hearns,

 The cluster is installed using Platform cluster Manager (PCM). LSF is installed but no OpenMPI application is yet integrated with LSF.
 WRF help gave me following instructions.

mpirun -v -machinefile ~/mach.conf -np 2 wrf.exe

Please talk to your computer manager about how to setup mach.conf and allow communications between nodes.

 you have a Dell cluster. Can we ask which company installed the
cluster, and who manages the cluster?
The company who installed it should have given you some documentation
on how to run MPI jobs.

Also can we ask if there is a batch scheduler or workload management
software on this cluster?
I ask because if there is PBS, Gridengine, LSF etc. installed there
will be an 'integration; with OpenMPI
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