Ansys Fluent 2020R2 through RSM - Write permission error after 5900 time steps
 

Hi all,

I was wondering if any of you have experience with the following error. Setup:
- Ansys Fluent 2020R2, used in batch mode through Ansys Workbench and RSM. Solve is conducted on a local HPC system (Windows HPC, so you may start laughing already).
- 3D case with a transient SBES combustion simulation, with FGM combustion model, DO radiation. The Fluent NOx post-processor is active as well, with 10 iterations with per time step.
- Case has some process automation in there so start-up the flame slowly.
- Every time step monitor files are written for temperature, O2 mass fraction, CH4 mass fraction and NO mass fraction, as well as there time average (statistics) values.
- Every 5 time steps two animations are saved in .hsf format
- Every 50 time steps 1 animation is saved in .png format (for tracking during solve)

After about 5900-6000 time steps (of the planned 9000 time steps) I get the following error:

Following report-files are not valid:
furnaceoutlet-ch4-massfrac-mwa-rfile:
Folder <dirpath>\projects\bhxa5ifv.uvy\. does not have write permission.

Run can not be started until validation issues are resolved.
Deactivate invalid report clients to continue? [no] (wb-save #t)Please answer y[es] or n[o].
.

Combustion simulations are nothing new to us (we do this for a living), but this particular error I have never seen before. I have had this error 3 times now and it drives me absolutely mad, as this simulation takes about 36 hrs. The exact amount of time steps after which this occurs seems to vary. If I add more monitor files or animation files, the error appears to prompt after a lower amount of time steps. However, it is not the storage space that is limiting here, as we have 750 TB free space in that project directory.

Is there a maximum amount of files in a single folder defined for RSM usage? Because the maximum limit for NTFS formatted drives is far above the amount of files that are written at the point of the crash.

Much appreciated!