Category: MPI

How to compile HPL (LINPACK)

This guide will show you how to compile HPL (Linpack) and provide some tips for selecting the best input values for hpl.dat based on my experiences at the student cluster competitions. This benchmark stresses the computers floating point operation capabilities. Although just calculating FLOPs is not reflective of applications typically...

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How to use MPI without NFS

You can use MPI without NFS or a shared file system! We had a situation where we couldn’t find the NFS server or client packages for arm64 for Ubuntu 16.04. We had OpenMPI version 1.10.2 installed on 2 nodes without NFS. When you use MPI without NFS, you need to ensure...

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How to Fix OpenMPI ORTE Error: unknown option “–hnp-topo-sig”

We encountered an ORTE bug with the error message, Error: unknown option “–hnp-topo-sig”, while using OpenMPI version 1.10.2 for arm64 on Ubuntu 14.04 server. More specifically, we ran the following command using 2 nodes with MPI: mpirun –hostfile /nfs/hostnames -n 4 /nfs/mpi-hello-world/mpi_hello_world

ORTE errors can happen because of a variety of...

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Running MPI – Common MPI Troubleshooting Problems

In this post, I’ll list some common troubleshooting problems that I have experienced with MPI libraries after I compiled MPICH on my cluster for the first time. The following assumes that: You have at least 2 nodes as part of your cluster. You have MPI compiled inside a NFS (Network...

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