<html>#2287: add OpenMPI env vars to notebook to avoid warning messages du to vader library in containers
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<tr><td style='text-align:right'> Reporter:</td><td>Roland Haas</td></tr>
<tr><td style='text-align:right'> Status:</td><td>new</td></tr>
<tr><td style='text-align:right'>Milestone:</td><td></td></tr>
<tr><td style='text-align:right'> Version:</td><td></td></tr>
<tr><td style='text-align:right'> Type:</td><td>bug</td></tr>
<tr><td style='text-align:right'> Priority:</td><td>minor</td></tr>
<tr><td style='text-align:right'>Component:</td><td>EinsteinToolkit Virtual Machine</td></tr>
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<p>Comment (by Roland Haas):</p>
<p>Adding the vader env setting</p>
<div class="codehilite"><pre><span></span>export OMPI_MCA_btl_vader_single_copy_mechanism=none
</pre></div>
<p>also helps prevent MPI hangs in OSX VirtualBox containers (OSX being the client) when using MacPorts as described in #2290 . The same hang still occurs in OSX Catalina VMs. This may be related to an actual bug on OpenMPI: <a data-is-external-link="true" href="https://github.com/open-mpi/ompi/issues/6568" rel="nofollow">https://github.com/open-mpi/ompi/issues/6568</a> and affects only MPI communication with large packages (which likely explains why not every single MPI using test would hang). The OpneMPI ticket provides what looks like a reproducer.</p>
<p>I would like to add this env variable setting (with a comment about Docker and OSX virtual machines) to the tutorial notebook (I will also use it for my own VMs to run the testsuite but that is somewhat unrelated).</p>
<p>--<br/>
Ticket URL: <a href='https://bitbucket.org/einsteintoolkit/tickets/issues/2287/add-openmpi-env-vars-to-notebook-to-avoid'>https://bitbucket.org/einsteintoolkit/tickets/issues/2287/add-openmpi-env-vars-to-notebook-to-avoid</a></p>
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