Doing the fork/exec with an environment that omitted the variables whose names started with either 'OMPI' or 'PMIX' did the trick.
On Sat, Jul 11, 2020 at 6:04 PM John Retterer <john.rette...@gmail.com> wrote: > Thank you, Ralph. I was afraid that was the reason it didn’t work but I > wanted to be sure. > > John > > > On Sat, Jul 11, 2020 at 5:37 PM Ralph Castain via users < > users@lists.open-mpi.org> wrote: > >> You cannot cascade mpirun cmds like that - the child mpirun picks up >> envars that causes it to break. You'd have to either use comm_spawn to >> start the child job, or do a fork/exec where you can set the environment to >> be some pristine set of values. >> >> >> > On Jul 11, 2020, at 1:12 PM, John Retterer via users < >> users@lists.open-mpi.org> wrote: >> > >> > From the rank #0 process, I wish to start another mpi job (to create >> some data to be used by the parent job). >> > I'm trying to do this with the command >> > >> > istat= system( "/...path.../mpirun -np 2 /...path.../prog2 args >> >file.log 2>&1" ) >> > >> > within the code executed by the rank #0 process, where ...path... is >> the path to the executables, prog2 is the daughter program, and args its >> arguments. >> > >> > On return, the status istat = 256, and, although the log file file.log >> has been created, it is empty. >> > >> > DOes anybody have an idea why this doesn't work? >> >> >>
