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--- workshops:hpcprac3 [2017/07/05 10:08]
kevin
+++ workshops:hpcprac3 [2021/12/09 16:42] (current)
@@ Line 103: / Line 103: @@
 </code>
-Compile this with the **mpicc** MPI C compiler.
+Compile this with the **mpicc** MPI C compiler:
-> Those of you who prefer Fortran will need to compile your hello_mpi.f90 with the **mpif90** compiler instead:
+  mpicc -o hello_mpi.x  mpi_hello.c
+> Those of you who prefer Fortran will need to compile your hello_mpi.f90 with the **mpif90** compiler instead.
 <code Fortran>
@@ Line 120: / Line 122: @@
 end
 </code>
+> Compile the Fortran example with:
+  mpif90 -o hello_mpi.x   mpi_hello.f90
 If you get an error message complaining that **mpicc** (or **mpif90**) is not found, then you forgot to load the necessary modules:
@@ Line 134: / Line 142: @@
 ) gcc/5.1.0                      2) chpc/openmpi/2.0.2/gcc-5.1.0
 </code>
+Now create a job script file to run your first MPI program, and save it as //hello.pbs//:
+<code bash>
+#!/bin/bash
+#PBS -N Hello
+#PBS -l select=1:ncpus=24:mpiprocs=24
+#PBS -P Wchpc
+#PBS -q R522145
+#PBS -W group_list=training
+#PBS -l walltime=4:00:00
+module load chpc/openmpi/2.0.2/gcc-5.1.0
+cd /mnt/lustre/users/studentNN/MPI
+CWD=`pwd`
+echo "Working directory is $CWD"
+nproc=`cat $PBS_NODEFILE | wc -l`
+echo "nproc = $nproc"
+echo "Nodes used by this job:"
+cat $PBS_NODEFILE
+echo "Starting run..."
+echo "======="
+mpirun -n $nproc ./hello_mpi.x
+echo "======="
+echo "... done."
+</code>
+Launch the job script with **qsub**:
+  qsub hello.pbs
+Check its status with **qstat**:
+  qstat | grep student00
+> Replace the ''00'' above with your student account number!
+Once your job status has changed from ''R'' to ''F'' or ''E'' then look for the output:
+  ls
+The file you want to look at will be called something like //Hello.o99999// where the number at the end will be the job ID number:
+  cat Hello.o12345
+> Replace 12345 with the job number!
+=====Carry On=====
+Attempt the exercises in the {{:workshops:epcc-mpi-course-slides.pdf|slides}}.

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