mpiexec was unable to launch the specified application (Raspberry pi)

Question

I get the same error for each of the 3 following commands. is my ip address from ifconfig. Any ideas on what is going wrong? It worked fine last night.

mpiexec -f machinefile -n <number> hostname
mpiexec -f machinefile –n 1 hostname
mpiexec -f machinefile -n 2 ~/mpich_build/examples/cpi
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mpiexec was unable to launch the specified application as it could not find an executable:

Executable: -f
Node: raspberrypi

while attempting to start process rank 0.
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I'm following the tutorial from http://www.southampton.ac.uk/~sjc/raspberrypi/pi_supercomputer_southampton.htm

Answer 1

My guess is that you've installed OpenMPI, as vs MPICH2 as given in the examples, yes? There's nothing wrong with that, but the options for things like specifying machine files are somewhat different. You'll want

mpiexec -machinefile machinefile -n 1 hostname

etc.