Running Lumerical in Terminal with only checking Solver licenses

[martinmi]

Hi all, 

I have an ongoing problem, or maybe a misunderstanding on my part, that I have been unable to solve for a long time.

I am trying to start Lumerical using only solver licenses on my Linux RHEL8 server. To do so, I am using the following command taken from (Link to article):

• /opt/lumerical/2024-r2.3/bin/eme-engine -t 30 ~/Desktop/Lumerical/Test_EMSim.lms -use-solve

When I check the solver licenses, I am unfortunately checking out only one. However, when I use the FDTD solver with the command:

• /opt/lumerical/2024-r2.3/bin/fdtd-engine -t 30 ~/Desktop/Lumerical/Test_FDTDSim.lms -use-solve

I am able to check out 14 licenses. Can someone please explain what I am doing wrong and how I can fix it?

I am running both commands on the same server, with the same parameters, the same OS, the same environment variables, and the same version of Lumerical.

Best regards, 
Martin 

 

 

[Lito]

Hi Martin, 

When running the simulation files directly from the command line/terminal there is no need to add/use the -use-solve flag/argument. The engine executable/binaries will be only using the solve licenses.

Run EME simulations (.lms) files:  

/opt/lumerical/2024-r2.3/bin/eme-engine -t 30  eme_simulationfile.lms

Run FDTD simulations (.fsp) files: 

/opt/lumerical/2024-r2.3/bin/fdtd-engine -t 30  fdtd_simulationfile.fsp

The GUI license is only used when you open/run the Lumerical CAD/IDE or run the Lumerical API/Python (.py) or Lumerical (.lsf) scripts. If you run a script the runs a simulation file, then you will be using both the GUI and the SOLVE licenses. 

Hope this helps. Let me know if you have any questions. 

[martinmi]

Hi Lito, 

thanks for the quick replay and the helpful advice. I tried the two commands again without the “-use-solve” at the end, and still the FDTD command checks 14 solver licenses and the EME command only uses one. Could it be something else I need to check/set up on my site that I may be overlooking?

Best regards, 

Martin 

[Lito]

@martinmi,

How are you checking the license usage/consumption on your license server? Are you checking the license usage as shown in this KB? Or from the Ansys license management center as shown here? 

What is the license usage prior to running your simulations? Does it show the number of licenses available or in use? e.g. all licenses are available shown below.  

Are other users using the licenses? Are there stuck or abandoned licenses? See the following KB for more information: 

>> What happens when you lose connection to the license server? – Ansys Optics 

>> How to release a stuck, ghost or abandoned license – Ansys Optics

 

Example license usage/consumption report from Ansys LM / FlexNet lmutil: 

lmutil - Copyright (c) 1989-2023 Flexera. All Rights Reserved. 
Flexible License Manager status on Thu 3/6/2025 15:56 
[Detecting lmgrd processes...] 
License server status: 
License file(s) on C:\Program Files\ANSYS Inc\Shared Files\Licensing\license_files\ansyslmd.lic: 
license server UP (MASTER) v11.19.5 
Vendor daemon status : 
ansyslmd: UP v11.19.5 
Feature usage info: 
Users of lum_eme_solve: (Total of 1 license issued; Total of 0 licenses in use) 
Users of lum_fdtd_solve: (Total of 1 license issued; Total of 0 licenses in use) 

[martinmi]

Hi Lito, 

For me, the university manages the licenses on a server. So we have a website where I can check the GUI and solver licenses checked by me or other users in real time. There I can see that I check 14 solver licenses when using the FDTD command and only one solver license when using the EME. I will check the linkas the next few days and try to get more information.

Thanks for the quick recap. 

Best regards, 

Martin 

[Lito]

Hi Martin,

If you are still seeing license being checked out even if you are not running any simulations, then there is something wrong. Those licenses are stuck/abandoned and should be released by the license server after 2-3 hours.

Alternatively. check the license status which machine is using/checking out the licenses and kill any "fdtd-engine" processes running on the machine.  

Otherwise, if there are no fdtd-engine processes running on the machines, the licenses will have to be manually release by the IT/admins as shown in our KB (sudo root access required). 

[martinmi]

Hi Lito, 

Thank you very much for the quick reply. The suggestions did not help, but I will still try to understand the problem. Maybe it's not with my site but with the it is a problem with the license manager as you suggested. I will have to talk to our license manager administrators. 

Best Regards, 

Martin