Tagged: MPI

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 that the same version of MPI is installed by every node. Then, you have to ensure that the same data files, which include the program, hostnames file, and input files,...


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 different things, but it’s usually because your mpirun is not the same version as your mpi compiler. Even if you think that you only have one MPI version, you may in...


How to Compile HPCG

HPCG, which stands for High Performance Conjugate Gradients, is a benchmark project to create a new metric for ranking HPC systems. HPCG measures the performance of basic operations including sparse matrix-vector multiplication, sparse triangular solve, vector updates, global dot products and more. The implementation is written in C++ with MPI and OpenMP support. http://www.hpcg-benchmark.org/software/index.html   HPCG Reference Code There are versions of HPCG optimized for NVIDIA GPUs or Intel XEON Phis. For this blog post, I’ll show you how to...


How to Setup the Intel Compilers on a Cluster

Intel compilers like icc or icl are very useful for any cluster with Intel processors. They’ve been known to produce very efficient numerical code. If you are still a student, you can grab the student Intel Parallel Studio XE Cluster Edition, which includes Fortran and C/C++ for free for a year. Here’s our experience. If you need more information, definitely check out the official Intel Parallel Studio XE Cluster Edition guide. Dependencies You should have the GCC C and C++...


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 File System), a shared folder. I will divide the common problems into separate sections. For my first installation of an MPI library, I was using http://www.mpich.org/downloads/   MPI Paths on each...