title: Mpi Bcast Error while using Calcul Canada
body: <p>I am trying to run a calculation on the calcul canada remote site from my MAC. this is the input file run.sh I am using:
  <code>#!/bin/sh</code></p>
  
  <pre><code>#SBATCH --nodes=4
  
  #SBATCH --ntasks-per-node=32
  #SBATCH --time=24:00:00
  #SBATCH --mem-per-cpu=2000M
  #SBATCH --account=def-jkopysci
  module load quantumespresso/6.4.1
  srun -n 128 pw.x -i &lt; espresso.scf.in &gt; sample.out`
  </code></pre>
  
  <p>After a few minutes, it outputs a slurm along with an output file. The output file is good but incomplete (a few iterations happen but then it stops). This is what the slurm contains:</p>
  
  <pre><code>`    [blg7239:222904] *** An error occurred in MPI_Bcast
  [blg7239:222904] *** reported by process [47353251107131,62]
  [blg7239:222904] *** on communicator MPI COMMUNICATOR 29 SPLIT FROM 26
  [blg7239:222904] *** MPI_ERR_TRUNCATE: message truncated
  [blg7239:222904] *** MPI_ERRORS_ARE_FATAL (processes in this communicator will now abort,
  [blg7239:222904] ***    and potentially your MPI job)
  srun: Job step aborted: Waiting up to 62 seconds for job step to finish.
  slurmstepd: error: *** STEP 8210518.0 ON blg7131 CANCELLED AT 2020-05-28T21:37:12 ***
  srun: error: blg9414: tasks 64-95: Killed
  srun: error: blg9415: tasks 96-127: Killed
  srun: error: blg7131: tasks 0-31: Killed
  srun: error: blg7239: tasks 32-61,63: Killed
  srun: error: blg7239: task 62: Exited with exit code 15`
  </code></pre>
  
  <p>why is this happening and how can I fix it? Please help!!!</p>