Running EME solver in Terminal

- July 2, 2024 at 2:11 pm
  
  martinmi
  Subscriber
  
  Hallo,
  I'm currently following the Lumerical Wiki article https://optics.ansys.com/hc/en-us/articles/360024974033-Running-simulations-using-terminal-on-Linux on how to run the solvers eme and fdtd in the terminal. I have a few difficulties:
  1) Running the following code "/opt/lumerical/v241/bin/eme-engine -t 400 ~/Downloads/EMERun1.lms -use-solve" should start the EME solver and it does. The only problem I have is the "-t 400" part. I only check one eme-solve license instead of several. When I use the equivalent fdtd command " /opt/lumerical/v241/bin/fdtd-engine -t 400 ~/Downloads/FDTDRun1.fps -use-solve", I check 1 + all avaivalben solver licenses in my package.
  
  2) Is there an option that allows me to run an EME propagate in this command line as well? I know I can have a special script with all the necessary commands and run it, but I'm trying to do everything in the terminal without additional scripts.
  
  Best regards,
  Martin
- July 2, 2024 at 6:24 pm
  Lito
  Ansys Employee
  @martinmi,
  Try to run MPI on Linux.
  >Running simulations with MPI on Linux – Ansys Optics
  e.g. Intel MPI:
```
/mpirun -n 400 /opt/lumerical/v241/bin/eme-engine-impi-lcl -t 1 simulationfile.lms 
/mpirun -n 400 /opt/lumerical/v241/bin/fdtd-engine-impi-lcl -t 1 simulationfile.fsp
```
  e.g. Open MPI:
```
/mpiexec -n 400 /opt/lumerical/v241/bin/eme-engine-ompi-lcl -t 1 simulationfile.lms 
/mpiexec -n 400 /opt/lumerical/v241/bin/fdtd-engine-ompi-lcl -t 1 simulationfile.fsp
```
  - July 3, 2024 at 9:47 am
    
    martinmi
    Subscriber
    
    I will try but i dont habe the admin rights in the moment to install Open MPI or Intel MPI on the Linux Server.
    I still dont get why i need to run OpenMPI or IntelMPI when i am not trying to run the simulation on other servers? And why when i am running the FDTD command i am able to see that i am checking all available FDTD Solver Licenses (1 + rest) like it said in the Lumerical artical that i linkt, but doing so with the EME engine i cannot?
    
    Best Reagrds,
    Martin
- July 4, 2024 at 1:56 am
  Lito
  Ansys Employee
  @Martin,
  If you are only running on the local computer (1 computer), you can run without MPI. Running with 400 threads (-t 400) on the local computer (localhost) will take up 13 solve licenses (400/32). Ensure that you have 400 threads on the local computer and you are not oversubscribing the number of threads that what is available on the local machine.
  >>Ansys optics solve, accelerator, and Ansys HPC license consumption – Ansys Optics
```
#try running without '-use-solve' argument
/opt/lumerical/v241/bin/eme-engine  -t 400 simulationfile.lms
/opt/lumerical/v241/bin/fdtd-engine -t 400 simulationfile.fsp
```
  You can check the running processes with top.
```
#run from terminal
top -H 
```
  With the (-H) argument, should show each eme engine process/cpu thread.