Mark, My understanding is that shell meta expansion occurs once on the first node, so from an Open MPI point of view, you really invoke mpirun echo node0 I suspect mpirun echo 'Hello from $(hostname)' Is what you want to do I do not know about mpirun echo 'Hello from $HOSTNAME' $HOSTNAME might be passed by the first node to all tasks, and hence might not have the value you expect on all the nodes Feel free to mpirun env | grep ^HOSTNAME= To check if the HOSTNAME variable is set to what you expect
/* i an afk, so i cannot check that right now ... */ Cheers, Gilles Mark Potter <mpot...@pcpcdirect.com> wrote: >This question is related to OpenMPI 2.0.1 compiled with GCC 4.8.2 on >RHEL 6.8 using Torque 6.0.2 with Moab 9.0.2. To be clear, I am an >administrator and not a coder and I suspect this is expected behavior >but I have been asked by a client to explain why this is happening. > >Using Torque, the following command returns the hostname of the first >node only, regardless of how the nodes/cores are split up: > >mpirun -np 20 echo "Hello from $HOSTNAME" > >(the behaviour is the same with "echo $(hostname)) > >The Torque script looks like this: > >#PBS -V >#PBS -N test-job >#PBS -l nodes=2:ppn=16 >#PBS -e ERROR >#PBS -o OUTPUT > > >cd $PBS_O_WORKDIR >date >cat $PBS_NODEFILE > >mpirun -np32 echo "Hello from $HOSTNAME" > >If the echo statement is replaced with "hostname" then a proper >response is received from all nodes. > >While I know there are better ways to test OpenMPI's functionality, >like compiling and using the programs in examples/, this is the method >a specific client chose. I was using both the examples and a Torque job >script calling just "hostname" as a command and not using echo and the >client was using the script above. It took some doing to figure out why >he thought it wasn't working and all my tests were successful and when >I figured it, he wanted an explanation that's beyond my current >knowledge. Any help towards explaining the behaviour would be greatly >appreciated. > >-- >Regards, > >Mark L. Potter >Senior Consultant >PCPC Direct, Ltd. >O: 713-344-0952 >M: 713-965-4133 >S: mpot...@pcpcdirect.com >_______________________________________________ >users mailing list >users@lists.open-mpi.org >https://rfd.newmexicoconsortium.org/mailman/listinfo/users _______________________________________________ users mailing list users@lists.open-mpi.org https://rfd.newmexicoconsortium.org/mailman/listinfo/users
