How to set additional_switches in launch_mapdl correctly?

[jinfaz567]

Hello everyone,

I'm encountering an issue when trying to use the launch_mapdl function from the PyAnsys library. Specifically, I'm getting an error when I include the additional_switches parameter with the value -acc nvidia -na 1. I have set this parameter based on the official documentation of PyAnsys_launch_mapdl, but it seems like the function call is not being handled correctly. Here's the code snippet that's causing the problem:

add_switches = "-acc nvidia -na 1"
mapdl = launch_mapdl(exec_file=ansys_path, run_location=path, override=True, nproc=processor_count,
                     additional_switches=add_switches, start_timeout=60, start_instance=True)

I'm passing the additional_switches parameter to enable GPU acceleration, , but it seems like there might be a misunderstanding in how it should be used.Can anyone provide some guidance on how to properly set the additional_switches parameter for GPU acceleration?

The complete error message is as follows:

PyMAPDL is taking longer than expected to connect to an MAPDL session.
Checking if there are any available licenses...
Traceback (most recent call last):
  File "D:\python39\env\pyans_ui\lib\site-packages\ansys\mapdl\core\launcher.py", line 624, in launch_grpc
    _check_file_error_created(run_location, timeout)
  File "D:\python39\env\pyans_ui\lib\site-packages\ansys\mapdl\core\launcher.py", line 671, in _check_file_error_created
    raise MapdlDidNotStart(msg)
ansys.mapdl.core.errors.MapdlDidNotStart: MAPDL failed to start.
No error file (.err) generated in working directory.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "D:\python39\env\pyans_ui\lib\site-packages\ansys\mapdl\core\launcher.py", line 1795, in launch_mapdl
    port, actual_run_location, process = launch_grpc(
  File "D:\python39\env\pyans_ui\lib\site-packages\ansys\mapdl\core\launcher.py", line 641, in launch_grpc
    raise MapdlDidNotStart(msg) from e
ansys.mapdl.core.errors.MapdlDidNotStart: MAPDL failed to start.
No error file (.err) generated in working directory.
Run location: C:\Users\ADMINI~1\AppData\Local\Temp\ansys_ipmnykjmxw
Command line used: "E:\Program Files\ANSYS Inc\v211\ansys\bin\winx64\ANSYS.exe" -j file -np 4  -b -i .__tmp__.inp -o .__tmp__.out -acc nvidia -na 1 -mpi msmpi -port 50052 -grpc



During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "F:\code\ui_submit\test_main.py", line 2401, in <module>
    mapdl = launch_mapdl(exec_file=ansys_path, nproc=processor_count, additional_switches=additional_switches)
  File "D:\python39\env\pyans_ui\lib\site-packages\ansys\mapdl\core\launcher.py", line 1831, in launch_mapdl
    lic_check.check()
  File "D:\python39\env\pyans_ui\lib\site-packages\ansys\mapdl\core\licensing.py", line 191, in check
    raise LicenseServerConnectionError("\n".join(self._license_file_msg))
ansys.mapdl.core.errors.LicenseServerConnectionError: Exceeded timeout of 45 seconds while examining:
C:\Users\ADMINI~1\AppData\Local\Temp\.ansys\licdebug.FEAT_ANSYS.211.out

Process finished with exit code 1

[mikerife]

Hi @jinfaz567 what is the licensing like there? Since nproc=4 the use of the GPU requires at least one HPC or HPC pack license. Do you know if those are available to you? If not try setting nproc=3 and try again. Mike

[jinfaz567]

Hi @mikerife Thank you very much for your reply! But I don't know how to check the HPC license, and when I try to set nproc=3, it still doesn't work.

[germa89]

It seems to me you are using it right, the error message shows the additional switches in the command line call:

"E:\Program Files\ANSYS Inc\v211\ansys\bin\winx64\ANSYS.exe" -j file -np 4  -b -i .__tmp__.inp -o .__tmp__.out -acc nvidia -na 1 -mpi msmpi -port 50052 -grpc

I would inspect any error file in C:\Users\ADMINI~1\AppData\Local\Temp\ansys_ipmnykjmxw to say any further info.

If the error file is not useful, you can always open a Command Prompt windows (preferable in C:\Users\ADMINI~1\AppData\Local\Temp\ansys_ipmnykjmxw), and execute the "E:\Program Files\ANSYS Inc\v211\ansys\bin\winx64\ANSYS.exe" -j file -np 4 -b -i .__tmp__.inp -o .__tmp__.out -acc nvidia -na 1 -mpi msmpi -port 50052 -grpc, and see the error message.