Running and Verifying FDS

Procedure

Use PuTTY to log in to the server as the root user.
Run the following command to switch to the FDS directory:
```
cd /path/to/FDS/fds-FDS6.7.4/
```
Run the following command to create a testcase directory:
```
mkdir testcase
```
Run the following command to go to the testcase directory:
```
cd testcase
```
Run the following command to set the number of OpenMP threads to 1:
```
export OMP_NUM_THREADS=1
```
Run the following command to create a hostfile file and add node information:
```
echo -e 'node1\nnode2\n…\nnodex' > /path/to/HOSTFILE
```
- In the preceding command, node1, node2, ..., and nodex indicate the host names of the nodes. You can run the hostname command to query the host names. \n indicates a newline character.
- This step is mandatory when multiple nodes are running and can be skipped when only one node is running.
Run the following commands to run FDS:
- Single node
```
`which mpirun` -np 128 --mca btl ^openib --allow-run-as-root ../../Build/mpi_gnu_linux_64/fds_mpi_gnu_linux_64 ../../Validation/MPI_Scaling_Tests/FDS_Input_Files/weak_scaling_test_128.fds
```
  If the command is successfully run on a single node, the following information is displayed:
```
STOP: FDS completed successfully (CHID: weak_scaling_test_128)
```
- Multiple nodes
```
`which mpirun` -N 128 -x OMP_NUM_THREADS -x PATH -x LD_LIBRARY_PATH --hostfile /path/to/HOSTFILE --mca btl ^openib --allow-run-as-root ../../Build/mpi_gnu_linux_64/fds_mpi_gnu_linux_64 ../../Validation/MPI_Scaling_Tests/FDS_Input_Files/weak_scaling_test_288.fds
```
  In the preceding case, the value of X in weak_scaling_test_X.fds must be greater than the total number of CPU cores used for the running. For example, if two nodes need to use test cases whose X is greater than or equal to 256, set weak_scaling_test_X.fds to weak_scaling_test_288.fds.
Check the value of real in the fds.log log. The unit is second. A smaller value indicates better performance.

Figure 1 shows an example.

Figure 1 Result example

Parent topic: FDS 6.7.4 Porting Guide (CentOS 7.6)