Intel MPI environment when running FDS on multiple machines (network)

[nielss...@gmail.com]

Hello,

At our office we're having multiple computers which we would like to run one FDS calculation simultaniously over the local network.

We have tried the connection and the computers do seem to recognize eachother. We have also installed the latest version of FDS (6.4.0) on both machines.

A test FDS file which runs fine on a single machine is placed in a shared map on one computer as a test file.

Both computers run on windows 7.

When we try to start the calculations we get an error message telling us that the "pmi_proxy is not found" and to "set intel MPI environment variables". (see the attached screenshot)

We could not (yet) find anything about this in the user guide or in the google groups.

Also when i try step 4 of paragraph 3.2.2 of the latest user guide (using mpiexec -hosts 1 m1 2 -wdir \\...\... fds job_name.fds) to check if it works running on my own machine, the fds file does start running.. so i believe the paths we are providing in DOS are correct and the problem lies somewhere with the MPI variables.

Could it be that this has something to do with the computers running on Windows 7?

I hope anyone can help me with this.

Kind regards,

Niels

[Kevin]

Is this a Windows Domain Network; that is, can you log in to both machines using the same username and password?

What happens when you type

mpiexec -hosts 2 machine1 1 machine2 1 test_mpi

[Niels Strating]

Hi Kevin,

Thanks for your reply!

Both machines are windows 7 machines and i can login on both computers using identical username and password.

When i type the string you suggest it gives me the message to "set intel MPI environment variables" (see the screenshot).

I tried pingin from both machines to the other and both ping without any losses. I also tried the suggested string from the other computer, this one asks me to enter my login credentials and password, though when i do it prompts the samen error about the mpi environment variables.

Do you have any other suggestions?

Thanks

Op vrijdag 15 april 2016 17:26:12 UTC+2 schreef Kevin:

[Kevin]

On both machines, make sure you have installed the latest version of FDS. Reboot both machines. On both, do a

where mpiexec

to determine if the mpiexec command is the one that comes with the FDS download. That is, make sure there is no other version of MPI installed.

[Niels Strating]

I got it working now. Seemed the FDS installations needed to be in the same folder. I renamed the path of the FDS folder on my own computer; i think that's why it was not recognized.

Now both folders have the same path and the calculation runs on two computers.

Thanks!

Op dinsdag 19 april 2016 12:47:30 UTC+2 schreef Kevin:

[Kevin]

That makes sense.

Lesson for all -- always install FDS where it is recommended. We have not really tested other configurations.

[John Van Workum]

I just wanted to add that you may see a significant performance hit when running across standard Ethernet between your computers. If you require multiple runs for example, it maybe best to utilize each workstation running it's own simulation rather than running over Ethernet for each run for optimal performance. To really take advantage of MPI, you need a very fast network such as Infiniband.

[Kevin]

With the latest version of FDS, there is a file printed out at the end of a run called job_name_cpu.csv. For each MPI process, the file lists the wall clock time spent in the major routines. Look at COMMunications and decide if the cost of communications is unacceptably high. Depends on the case.