Parallel Programming Guide for HP-UX Systems

MPI
Running
Chapter 2 47
mpiexec The MPI-2 standard defines mpiexec as a simple method to start MPI applications.
It supports less features than mpirun, but it is portable. mpiexec syntax has three formats:
• mpiexec offers arguments similar to a MPI_Spawn call, with arguments as shown in the
following form:
mpiexec [-n maxprocs ][-soft ranges ][-host host ][-arch arch ][-wdir dir ][-path
dirs ][-file file ] command - args
For example:
% $MPI_ROOT/bin/mpiexec -n 8 ./myprog.x 1 2 3
creates an 8 rank MPI job on the local host consisting of 8 copies of the program myprog.x,
each with the command line arguments 1, 2, and 3.
• It also allows arguments like a MPI_Spawn_multiple call, with a colon separated list of
arguments, where each component is like the form above.
mpiexec above : above : ... : above
For example:
% $MPI_ROOT/bin/mpiexec -n 4 ./myprog.x : -host host2 -n 4
/path/to/myprog.x
creates a MPI job with 4 ranks on the local host and 4 on host2.
• Finally, the third form allows the user to specify a file containing lines of data like the
arguments in the first form.
mpiexec [-configfile file ]
For example:
% $MPI_ROOT/bin/mpiexec -configfile cfile
gives the same results as in the second example, but using the -configfile option (assuming
the file cfile contains -n 4 ./myprog.x -host host2 -n 4 -wdir /some/path ./myprog.x)
where [ mpiexec_ options ] are:
-n maxprocs Create maxprocs MPI ranks on the specified host.
-soft range-list Ignored in HP MPI.
-host host Specifies the host on which to start the ranks.
-arch arch Ignored in HP MPI.
-wdir dir Working directory for the created ranks.
-path dirs PATH environment variable for the created ranks.