Learning Forum

[rkoomul]

I am looking for help to run a fluid structure interaction (FSI) simulation using a Linux cluster. The FSI problem I am trying to run is the Reed valve tutorial that comes with Ansys 2022R1.  This involves Fluent, Transient Structural, and System Coupling. I am able to run it using the Windows installation of Ansys on my Laptop (using a student license).  However, when I try the same simulation on the Linux cluster, I get an error message "Could not connect to System Coupling Services" (See the attached image).   I am using an academic/research license for Ansys on the Linux cluster.  Any pointers on how to fix this issue will be greatly appreciated.

Thank you for your help.

[Atul Singh]

I am not an ansys employee and just a user like you. But I am pretty sure, you will get a response from them, something on the lines of like, "Read the manual again". "Check the licenses", or "Forget about it".

Good luck.

[Rahul]

Hi 

Could you please try once after disabling 'Distributed' option in Mechanical and see if it works? Thanks.

[rkoomul]

Thank you for the suggestion. I tried it. But, still getting the same error message. Please see the attached image.

[Rahul]

Hi 
I tried running same tutorial on linux and it works. What configuration you are using for your linux run?

[rkoomul]

Our operating system is RHEL Server 7.9.  The Linux cluster is comprised of 8192 compute cores connected by low-latency Fourteen Data Rate (FDR) and Enhanced Data Rate (EDR) InfiniBand networks, with mainly Intel Xeon E5-2680 v4 and Intel Xeon Gold 6248R chips.  Also, I am using OnDemand version: v1.6.25 to run Ansys interactively.

[George Karnos]

 

Are there any firewalls in place or IP TABLES that could possibly be blocking communication between the programs?

 

[rkoomul]

Thank you George for the comment.  I was able to point to the correct license server and able to run the FSI simulation. It completed the required time steps, and gave a message "System coupling run completed successfully".  However, afterwards it gave an error message "Update failed for the Solution component in System Coupling. The coupled update for system Transient Structural thew an exception.  Unable to determine if file .../dp0/global/MECH/SYS.mechdb is open. Connection refused" (Please see the attached image).  Any suggestion how to fix this. Thank you. 

[m210025]

Hi rkoomul,

I'm facing the same issues as you regarding starting the simulation, may i know how did you get it to run? I'm also running on a linux cluster 

 

[rkoomul]

Our license resides on another Linux cluster.  So, our sys. admin. set correct environment variable for the license file location and it worked.

[m210025]

Hi rkoomul,

could you ask your sys admin explain in more details such that i can forward to my school's hpc side to look into it as well? It would really help my PhD research going forward!

Thank you!

[rkoomul]

In my case, I had set the environment variable CDLMD_LICENSE_FILE to a wrong location in my .bahrc file.  So, Ansys was looking for the license file there during system coupling. So, we changed it to correct location and it worked. 

[m210025]

Hi rkoomul,

thank you for the swift reponse! i will check in with my HPC side to see if they can make something out of it.