mpirun no longer works in blueCFD-Core 2.3-1, after installing blueCFD-Core 2016-1

Reason

The MS-MPI 7.1 library that is installed by default into Windows with the blueCFD-Core 2016 installer, is in conflict with the MS-MPI 2012 that blueCFD-Core 2.3-1 uses by default.

Solution

There are 4 possible solutions:

1. Simply copy the DLL file
2. Change the default MPI option
3. Add support for MS-MPI 7.1 in blueCFD-Core 2.3-1
4. Uninstall MS-MPI 7.1 from Windows

Solution 1 - Simply copy the DLL file

1. The simplest way is to get a copy of the necessary library msmpi.dll into the same folder as the binary you’re trying to run. To do so, use one of the following steps:

   1. Start an MSys terminal for blueCFD-Core 2.3-1.

   2. Run the following command:

      which simpleFoam
      

      Change the name simpleFoam to whichever the name of the binary you want to use.

   3. Now depending on the path given, you need to switch to that folder. When in doubt, you can use either one of the following commands:

      cd $FOAM_APPBIN
      cd $FOAM_USER_APPBIN
      

   4. Now, we get a copy of the necessary MS-MPI library by running:

      cp $MPI_ARCH_PATH/bin/msmpi.dll ./
      

   5. It should now be fully operational and ready to go! Go back to the case folder and try running your application in parallel once more. You can go back to the previous folder where you were working on by running:

      cd -
      

Note: Many thanks to Anh Vo from the MS-MPI team who gave us feedback on this and reported that the issue was related to the lookup mechanism in Windows, as detailed here.

Solution 2 - Change the default MPI option

Another possibility is to change the default MPI option in blueCFD-Core 2.3-1 to Open-MPI, although this means that users must use foamJob and not mpirun directly.

• This can be done by going to Windows Start Menu -> blueCFD-Core 2.3 -> Settings -> MPI.

Solution 3 - Add support for MS-MPI 7.1 in blueCFD-Core 2.3-1

Or a patch installer for blueCFD-Core 2.3-1 that provides support for MS-MPI 7.1 can be created by blueCAPE.

If you need this option, please use the Issue tracker or use the Contact form.

Solution 4 - Uninstall MS-MPI 7.1 from Windows

Uninstall MS-MPI 7.1 from Windows, through the Windows Uninstall interface.

Notes:

• Installing MS-MPI 7.1 is only needed to get the initial configurations up and running, so that blueCFD-Core 2016 could use the local installation of MS-MPI 7.1. Therefore, uninstalling it will make both versions work independently just fine.

• Nonetheless, in order to use multiple machines in parallel for cooperative runs, MS-MPI 7.1 must be installed in Windows.

• Note: Simply uninstalling it will not fully solve the problem, as further detailed in the next Q&A: Uninstalling MS-MPI 7.1 did not solve problem with mpirun in blueCFD-Core 2.3-1