Good morning, I just subscribed to this however I need some help. I really don't know much about MPICH however in my book Raspberry Pi Sper Cluster I am in a section that calls for this application to be installed. I have an issue when I try to run mpiexec commands, specifically mpiexec -f piprofile hostname. Command not found error. I am not even able to run mpiexec --version without the error. I clearly see them in the below path but I can execute anything. /media/witt/8efd83a8-d3be-4079-b8e3-6fceffff35bb/appdata/mpich4/install/bin# In my book the command they have for install is this; /media/witt/8efd83a8-d3be-4079-b8e3-6fceffff35bb/appdata/mpich4/mpich-4.2.2/configure \-prefix=/media/witt/8efd83a8-d3be-4079-b8e3-6fceffff35bb/appdata/mpich4/install What am I doing wrong. I have tried twice to install it and I get the same result each time command not found. I will day however That after the installation I can run mpiexec -f piprofile hostname and it works, however after about an hour or so I will ge the error message. Also my book references version 3.0.4 but I thought since the book was dated to find the latest. Best Regards Rich Martorano