Hey there, I am trying to set up a parallel invironment with 14 machines, running Linux XUbuntu, connected via ethernet. They all have same IP's and same hostnames. Well I started installing mpich-3.0.4 on a single machine, I run the cpi example on localhost by giving mpiexec -host localhost -n 4 ./examples/cpi and everything worked fine! So I continued changing the hostnames of 2 pc's for a start, and setting up the ssh in these two, also I installed the mpich-3.0.4 on the other machine too. By giving the ssh <othermachine> date commant , I get the date of the other host without giving a password, so I think I passed that step too. Next step was to check if the mpich-3.0.4 runs parallel, so I created a machine file (I made a text file giving the hostnames of the two computers , host1 and host2), and save it in my mpich-3.0.4 build directory. Though when I am trying to parallel run the cpi code by giving mpiexec -n 4 -f machinefile ./examples/cpi on my working directory, I get NO errors but neither parallel job... All processes still running on host1 which is my work station. What am I doing wrong? Thanks