Hi, Yes, I know why the keyfile is used for.
This is my intention to do replica of 2-3 members.

Hence can’t run with Security keyfile:
security:
authorization: enabled
KeyFile: /Users/jpolec/mongo_test/new_key

it doesn’t start with this on one server. On the other is works fine. So therefore I am confused.
Once it starts, then I will start doing replicas.