Hi Ralph, Good to know you've reproduced it. I was experiencing this using both the hostfile and host key. A simple comm_spawn was working for me as well, but it was only launching locally, and I'm pretty sure each node only has 4 slots given past behavior (the mpirun -np 8 example I gave in my first email launches on both hosts). Is there a way to specify the hosts I want to launch on without the hostfile or host key so I can test remote launch?
And to the "hostname" response...no wonder it was hanging! I just constructed that as a basic example. In my real use I'm launching something that calls MPI_Init. Evan
