Learning Forum

[Youngin Kim]

When I run a bit large simulation in Lumerical FDTD solutions, the FDTD solutions automatically terminates.

This also happens when I try to check the memory.

 

I have not seen this issue when I run the similar simulation in my past working places (both in Linux and Windows), but started to see this after moving my job.

 

The error message in the terminal is:

machine-name[Username/Desktop] lumerical fdtd-solutions
/home/Username/.config/Lumerica  - existing
Setup:rhel7.9i
/usr/pack/lumerical-2022_r1.1-bt/bin//fdtd-solutions: line 8: 11818 Segmentation fault      $FDTD_BIN_DIR/fdtd-solutions-app "$@"

I have tried to solve this within my department, but I could not.

Can I ask whether you have an idea how to solve this?

[Lito]

@Youngin Kim,

To clarify, are you having problems running the simulation file or you cannot open and run the CAD/GUI as shown in the error message? 

/usr/pack/lumerical-2022_r1.1-bt/bin//fdtd-solutions: line 8: 11818 Segmentation fault      $FDTD_BIN_DIR/fdtd-solutions-app "$@"

Based on the error message you are unable to open and run the FDTD CAD/GUI. See the KB for options on how to resolve OpenGL/graphics issues on your Linux. Consult with your IT to resolve the graphics issue on your Linux installation.   

>>> How to resolve system and OpenGL graphics related issues – Ansys Optics 

Best,
Lito

**Check out the Ansys Optics FAQs for answers to common and known issues**

[Youngin Kim]

I can open the simulation file and I am also able to edit it. But I can't run the simulation.

Please provide me other solution.

[Lito]

@Youngin Kim,

The error message you provided is not for running the simulation file -- this is when you are opening the FDTD CAD/GUI. The command "fdtd-solutions" is what you run for the CAD/GUI.  

How do you run the simulation file? Are you running from the CAD/GUI or from the command prompt/terminal and what command do you run to run the "simulation.fsp" file? 

Send a screenshot of your desktop opening and before running your simulation and screenshot of the error message - where you cannot run the "simulation.fsp" file.  

 

[Youngin Kim]

[Lito]

@Youngin Kim,

From your command, it seems that you are running a script that calls the FDTD GUI/CAD.  Please check with IT or the person who created the script/executable "lumerical fdtd-solutions" to check what is called by this script/executable. 

Typically we run the CAD (using the default install path for 2022 R1.1) 

/opt/lumerical/v221/bin/fdtd-solutions 

or in your case try opening the FDTD CAD?GUI directly from terminal. Do not use "lumerical fdtd-solutions"  

/usr/pack/lumerical-2022_r1.1-bt/bin/fdtd-solutions  

From your screenshot it shows "Segmentation fault error" -- there is something wrong with your installation. It's could be missing system or graphics libraries needed by the CAD/GUI see this Knowledge Base (KB) for details.

[Youngin Kim]

@Lito Yap,

I have tried your above suggestions with our IT person, but the results were same.

We have run the CAD in the directory that you have told us and we also checked the missing system, but IT person says we do not have any missing system or graphics libraries.

Would you please help us once more on this?

[Youngin Kim]

@Lito Yap

I have one more information to let you know.

This error happens when I run the simulation which having a light cource more than three.

It works when I set one or two sources in the FDTD simulation region.

However, I have successfully ran the FDTD simulations which have more than three sources (or even up to 16 sources) in the institutions where I worked in the past.

I do not know why this does not works in my current working place.

[Lito]

@Youngin Kim, 

from your message, 

However, I have successfully ran the FDTD simulations which have more than three sources (or even up to 16 sources) in the institutions where I worked in the past. I do not know why this does not works in my current working place.

We are unable to reproduce the issue on our Linux machines. We also do not know what is happening on your system/installation. 

This is probably an issue with your current system. Did your IT check for the required libraries as per this Knowledge Base (KB) > Installing on a shared filesystem on Linux – Ansys Optics ? These libraries should be installed or accessible by all nodes that will be running your simulation. 

Based on your screenshot, you are using an older version, 2022 R1.1 -- ask IT to install the latest release, Lumerical 2023 R1.3, available in the Ansys Optics downloads page. We use the latest versions that are available on our website for our tests/reproduction of the reported issues.

 

 

[Youngin Kim]

@Lito Yap

Our IT team tried all of the above suggestions, but it still does not work.

We also installed Lumerical solutions in my own machine, but this did not worked too.

Can we have a virtual meeting with me, our IT person and you? And share our screen to solve this issue?

[Lito]

@Youngin Kim, 

Is the issue happening to all computers on your network or only to a specific Linux machine?

Did you install the latest release of Ansys Lumerical on your local Windows computer or Linux machine? 

Does the issue happen to ALL simulations? Have you tried running the examples from our website? Ansys Optics Application Gallery (Apps). 

What is the error when running the example simulations on our website on a local Windows PC or your Linux machine? 

To debug this with your IT, please submit a support request to your Ansys account manager (AM) or your regional representative.  

 

 

[Youngin Kim]

Q:Is the issue happening to all computers on your network or only to a specific Linux machine?

A:All computers on our network

Q:Did you install the latest release of Ansys Lumerical on your local Windows computer or Linux machine? 

A: No, our CAD/softwear department does not have latest verson yet. 

Q: Does the issue happen to ALL simulations?

A: No, it only happens when I have multiple mode sources. This is written in my prior reply.

Q: Have you tried running the examples from our website? Ansys Optics Application Gallery (Apps).

A: Of course. The example works.

Q: What is the error when running the example simulations on our website on a local Windows PC or your Linux machine?

A: The example simulation in your website works.

To debug this with your IT, please submit a support request to your Ansys account manager (AM) or your regional representative. 

My Question: Where can I find my regional representative?

[Lito]

@Youngkin, 

Since the issue is only happening to specific simulations and not all simulation files, you will have to check on your simulation/project design. 

Check with your organization who bought Ansys Lumerical software from whom they bought or receive the Ansys Licenses. 

Or visit our > Contact Us (lumerical.com) page for more information.