PVM uses two environment variables when starting and running. Every PVM user needs to set these two variables to use PVM. The initial variable is PVM_ROOT, which is set to the location of the installed pvm3 directory. The second variable is PVM_ARCH , which notify PVM the architecture of this host. The simplest method is to set these two variables in your.cshrc file. Here is an example for setting PVM_ROOT:
setenv PVM_ROOT $HOME/pvm3
The user can set PVM_ARCH by concatenating to the file .cshrc, the content of file
$PVM_ROOT/lib/cshrc.stub.
Starting PVM
To start PVM, on any host on which PVM has been installed we can write
% pvm
The PVM console, called pvm, is stand-alone PVM tasks that let the user to interactively start, query, and change the virtual machine. Then we can add hosts to virtual machine by typing at the console prompt (got after last command)
pvm> add hostname
To delete hosts (excluding the one we are using ) from virtual machine we can write
pvm> delete hostname
We can see the configuration of the present virtual machine, we can write
pvm> conf
To see what PVM tasks are running on the virtual machine, we should write
pvm> ps -a
To close the virtual machine environment, we should write
pvm> halt
Multiple hosts can be added concurrently by typing the hostnames in a file one per line and then write
% pvm hostfile
PVM will then add all the listed hosts concurrently before the console prompt appears.
Compiling and Running the PVM Program
Now, we shall study how to compile and run PVM programs. To compile the program , modify to the directory pvm/lib/archname where archname is the architecture name of your computer. Then the following command are:
cc program.c -lpvm3 -o program
will compile a program known as program.c. After compiling, we can put the executable file in the directory pvm3/bin/ARCH. Also, we require to compile the program separately for each architecture in virtual machine. In case we use dynamic groups, we should also add -lgpvm3 to the compile command. The executable file will be run. To do this, first run PVM. After PVM is running, executable file might be run from the unix command line, similar to any other program.
PVM supplies an architecture-independent make, aimk, that automatically decides PVM_ARCH and links any operating system definite libraries to your application. To compile the C example, type
% aimk master.c
Now, from one window, start PVM and configure some hosts. In another window change directory to $HOME/pvm3/bin/PVM_ARCH and type
% master
It will ask for a number of tasks to be implemented. Then type the number of tasks.