Hello All,

I am trying to run an OpenMPI application across two physical machines.

I get an error "Returned "Unreachable" (-12) instead of "Success" (0)", and looking through the logs (attached), I cannot seem to find out the cause, and how to fix it.

I see lot of (communication) components being loaded and then unloaded, and I do not see which nodes pick up what kind of comm-interface.

At least one pair of MPI processes are unable to reach each other for
MPI communications.  This means that no Open MPI device has indicated
that it can be used to communicate between these processes.  This is
an error; Open MPI requires that all MPI processes be able to reach
each other.  This error can sometimes be the result of forgetting to
specify the "self" BTL.

  Process 1 ([[10782,1],6]) is on host: tik34x
  Process 2 ([[10782,1],0]) is on host: tik33x
  BTLs attempted: self sm tcp

Your MPI job is now going to abort; sorry.

The "mpirun" line is:

mpirun --mca btl self,sm,tcp --mca btl_base_verbose 30 -report-pid -display-map -report-bindings -hostfile hostfile -np 7 -v --rankfile rankfile.txt -v --timestamp-output --tag-output ./xstartwrapper.sh ./run_gdb.sh 

where the .sh files are fixes for forwarding X-windows from multiple machines to the machines where I am logged in.

Can anyone help?

Thanks a lot.