Learning Forum

[steven.vandenbrande]

I am trying to run Fluent 19.1.0 (without gui or graphics) on our new HPC cluster which runs Rocky Linux 8.6. Fluent however fails to spawn processes; this already happens when running on a single node with a single process:

 

 

@k28i14:vof_wice$ fluent 3ddp -ptrace -t1 -g -cnf=k28i14 -i simulation.jou
/ANSYS/19.1/ansys_inc/v191/fluent/fluent19.1.0/bin/fluent -r19.1.0 3ddp -ptrace -t1 -g -cnf=k28i14 -i simulation.jou
/ANSYS/19.1/ansys_inc/v191/fluent/fluent19.1.0/cortex/lnamd64/cortex.19.1.0 -f fluent -g -i simulation.jou (fluent "3ddp -pmpi-auto-selected  -host -r19.1.0 -t1 -mpi=ibmmpi -cnf=k28i14 -path/ANSYS/19.1/ansys_inc/v191/fluent -ptrace -ssh")
/ANSYS/19.1/ansys_inc/v191/fluent/fluent19.1.0/bin/fluent -r19.1.0 3ddp -pmpi-auto-selected -host -t1 -mpi=ibmmpi -cnf=k28i14 -path/ANSYS/19.1/ansys_inc/v191/fluent -ptrace -ssh -cx k28i14.:34149:46055
Starting /ANSYS/19.1/ansys_inc/v191/fluent/fluent19.1.0/lnamd64/3ddp_host/fluent.19.1.0 host -cx k28i14.:34149:46055 "(list (rpsetvar (QUOTE parallel/function) "fluent 3ddp -flux -node -r19.1.0 -t1 -pmpi-auto-selected -mpi=ibmmpi -cnf=k28i14 -ssh") (rpsetvar (QUOTE parallel/rhost) "") (rpsetvar (QUOTE parallel/ruser) "") (rpsetvar (QUOTE parallel/nprocs_string) "1") (rpsetvar (QUOTE parallel/auto-spawn?) #t) (rpsetvar (QUOTE parallel/trace-level) 1) (rpsetvar (QUOTE parallel/remote-shell) 1) (rpsetvar (QUOTE parallel/path) "/ANSYS/19.1/ansys_inc/v191/fluent") (rpsetvar (QUOTE parallel/hostsfile) "k28i14") )"

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Build Time: Apr 09 2018 13:46:05 EDT  Build Id: 10123

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Host spawning Node 0 on machine "k28i14" (unix).

Process is being spawned with command:
        /ANSYS/19.1/ansys_inc/v191/fluent/bin/fluent 3ddp   -flux -node -r19.1.0 -t1 -pmpi-auto-selected -mpi=ibmmpi -cnf=k28i14  -ssh -mportv ::45139:0

/ANSYS/19.1/ansys_inc/v191/fluent/fluent19.1.0/bin/fluent -r19.1.0 3ddp -flux -node -t1 -pmpi-auto-selected -mpi=ibmmpi -cnf=k28i14 -ssh -mportv ::45139:0
Failed to connect to k28i14

 

 

I have tried different values (default, intel, openmpi) for the -mpi option, but this all gives the same result. Leaving out the -cnf option, fluent does start. But unless I am mistaking, it will not be possible to run on multiple nodes.

I expect people will comment on this thread that there is something wrong with the ssh setup, but I can definitely tell that a simple ssh connection works without any password (it could still be there is a problem with launching a remote command over ssh, but I can't figure out which command fluent executes over ssh). As a further confirmation of this, with the newer Fluent version 2021R2, everything is working fine (i.e. I can do multi-node Fluent runs with that version).

On a side note, version 19.1.0 is working fine on another cluster that is running CentOS 7.

Do you have advice on what I could further try to get this working?

[Nikhil N]

Hello Steven, 

Looks like you are trying to run Fluent 19.1 on the unsupported version of Linux. Kindly have a look at this document which lists supported platforms for Release 19.2: ansys-191-platform-support-by-application.pdf

 

 

[Karim]

Hello Steven

Same problem with CENTOS 8.8 and ANSYS Fluent 2019R3.

Solved using -slurm option in the commande line : fluent 3d -t 1024 -slurm -pib

 

Karim