Hi Ralph and Gilles, Thanks for the suggestions.
I get the following error when I use --mca rmaps seq in the mpirun command. mpirun -hostfile host-file --mca rmaps seq -np 6 ./a1.out : -np 3 ./a2.out -------------------------------------------------------------------------- No nodes are available for this job, either due to a failure to allocate nodes to the job, or allocated nodes being marked as unavailable (e.g., down, rebooting, or a process attempting to be relocated to another node when none are available). -------------------------------------------------------------------------- $ cat host-file belenos568 belenos568 belenos569 belenos569 belenos570 belenos570 belenos568 belenos569 belenos570 I get the same error every time. If I remove the MCA parameter, it works. But, that's not with the MPI process distribution that I want. I am using OpenMPI 4.0.2. Any suggestion? Thanks, Vineet From: "users" <users@lists.open-mpi.org> To: "users" <users@lists.open-mpi.org> Cc: "Ralph Castain" <r...@open-mpi.org> Sent: Monday, 21 December, 2020 15:57:41 Subject: Re: [OMPI users] MPMD hostfile: executables on same hosts You want to use the "sequential" mapper and then specify each proc's location, like this for your hostfile: host1 host1 host2 host2 host3 host3 host1 host2 host3 and then add "--mca rmaps seq" to your mpirun cmd line. Ralph On Dec 21, 2020, at 5:22 AM, Vineet Soni via users < [ mailto:users@lists.open-mpi.org | users@lists.open-mpi.org ] > wrote: Hello, I'm having touble using the MPMD hostfile in which I want to place 2 executables on the same nodes. For example, I can do this using Intel MPI by: $ mpirun -machine host-file -n 6 ./EXE1 : -n 3 ./EXE2 $ cat host-file host1:2 host2:2 host3:2 host1:1 host2:1 host3:1 This would place 2 MPI processes of EXE1 and 1 MPI process of EXE2 on host1. However, I get an error if I define the same hostname twice in the hostfile of OpenMPI: $ mpirun -hostfile host-file -np 6 ./EXE1 : -np 3 ./EXE2 $ cat host-file host1 slots=2 max_slots=3 host2 slots=2 max_slots=3 host3 slots=2 max_slots=3 host1 slots=1 max_slots=3 host2 slots=1 max_slots=3 host3 slots=1 max_slots=3 Is there a way to place both executables on the same hosts using a hostfile? Thanks in advance. Best, Vineet
