How to run simulations in the background

When running simulations on a Linux machine, it may be helpful to run the simulation in the background or even allow the simulation to continue running even after the terminal window is closed.

Running FDTD simulations in Linux

The examples shown assume the following:

• FDTD Solutions is installed in the default location
• The simulation files are located in the current working directory of the terminal window.
• Example shown using [[ver]] release running with OpenMPI.

Run with the Terminal open

• Run the simulation with '&' at the end of your command,

mpiexec -n 16 /opt/lumerical/[[verpath]]/bin/fdtd-engine-ompi-lcl simulation.fsp &

• The Terminal can be minimized but cannot be closed.

Run with the Terminal closed 

• Run with 'nohup' at the beginning and '&> output.txt </dev/null &' at the end of your command,

nohup mpiexec -n 32 /opt/lumerical/[[verpath]]/bin/fdtd-engine-ompi-lcl simulationfile.fsp &> output.txt </dev/null &

• The Terminal can be closed.
• Errors and other information will be saved to 'output.txt'. 

Run sequentially with Terminal closed

• This process will use the bundled script. 'fdtd-run-local.sh' to run all FDTD simulations on the current working directory. 
• Run with 'nohup sh' at the beginning and '&> output.txt </dev/null &' at the end of your command,

cd /location_of/simulationfiles

nohup sh /opt/lumerical/[[verpath]]/bin/fdtd-run-local.sh -n 24 *.fsp &> output.txt </dev/null &

• The Terminal can be closed.
• Errors and other information will be saved to 'output.txt'.