Where to set the btl_openib_allow_ib MCA parameter to true！！

[LiuJiao0408]

hi all！！！
When I run examples, there is an error message：

[wangling@ln01 examples]$ mpirun -np 4 hello_c

By default, for Open MPI 4.0 and later, infiniband ports on a device
are not used by default. The intent is to use UCX for these devices.
You can override this policy by setting the btl_openib_allow_ib MCA parameter
to true.

Local host: ln01
Local adapter: hfi1_0
Local port: 1

---

---

WARNING: There was an error initializing an OpenFabrics device.

Local host: ln01
Local device: hfi1_0

Hello, world, I am 0 of 4, (Open MPI v4.1.0, package: Open MPI wangling@ln01 Distribution, ident: 4.1.0, repo rev: v4.1.0, Dec 18, 2020, 108)
Hello, world, I am 2 of 4, (Open MPI v4.1.0, package: Open MPI wangling@ln01 Distribution, ident: 4.1.0, repo rev: v4.1.0, Dec 18, 2020, 108)
Hello, world, I am 1 of 4, (Open MPI v4.1.0, package: Open MPI wangling@ln01 Distribution, ident: 4.1.0, repo rev: v4.1.0, Dec 18, 2020, 108)
Hello, world, I am 3 of 4, (Open MPI v4.1.0, package: Open MPI wangling@ln01 Distribution, ident: 4.1.0, repo rev: v4.1.0, Dec 18, 2020, 108)
[ln01:119050] 3 more processes have sent help message help-mpi-btl-openib.txt / ib port not selected
[ln01:119050] Set MCA parameter "orte_base_help_aggregate" to 0 to see all help / error messages
[ln01:119050] 3 more processes have sent help message help-mpi-btl-openib.txt / error in device init

I have seen several similar issues, but since I am not a professional in the relevant field, I have not found where to modify them. Where should I go to modify them?