MPI arguments for MPI jobs about hpc-toolkit HOT 1 CLOSED

From inspection, this does not appear related to any bug in the HPC Toolkit so I will convert it to a discussion.

On your question about mpiopt flags. I would recommend to try running fluent without any mpiopt flags and adding the -peth fluent flag. Please report if this works for you. If you still feel you have need for the mpiopt flags then please describe the requirements that require these flags.

On your specific question:

based on our understanding even though there is no Infiniband device, it should still work without any issue, is this understanding correct? (Referring to the use of I_MPI_FABRICS =shm:ofa" & "I_MPI_FALLBACK_DEVICE=disable).

I do not have personal knowledge to comment on you understanding of these flags, but as mentioned I do not believe they should be needed.

On your question:

What is the best configuration for using Slurm on GCP to run Ansys Fluent?

It is hard to make a definitive statement about what will work "best" as there are often trade offs based on price, performance, and the specific workload. Some general recommendations on a good configuration that has been shown to work well is:

• Use Intel MPI
• Use c2d-standard-112 compute nodes with SMT disabled (default on Slurm v5)
• Use a BASIC_SSD Filestore as a shared filesystem from which to run the fluent job

# Example filestore (could be /home instead of /shared)
  - id: sharedfs
    source: modules/file-system/filestore
    use: [network1]
    settings:
      local_mount: /shared
      filestore_tier: BASIC_SSD
      size_gb: 2560  # 2.5 * 1024

from hpc-toolkit.