The environment variable PVM_ROOT tells PVM where the system is installed, so one part can find another. It is the only thing that needs to be set in order to be able to run PVM. It must also be set when building the PVM installation from the source distribution.
If you normally use csh, add a line like this to your .cshrc file: setenv PVM_ROOT $HOME/pvm3
If you normally use sh,
add these lines to your .profile:
Make sure these are set in your current session too.
Older versions of PVM assumed an installation path of $HOME/pvm3. Versions 3.3 and later require that the PVM_ROOT variable always be set. Note: For compatibility with older versions of PVM and some command shells that don't execute a startup file when used with rsh, PVM_ROOT defaults to $HOME/pvm3 if it's not set.