I am in the process of upgrading my MongoDB replica set from 2.6 to 3.2. We are planning to create another replica set on the same set of machines as an option to fallback in case something goes wrong. In this context, I am trying to find out if the new mongod instance that i would install (on each of these servers to form a replica set) can point to the already existing data files folder being used by the live mongod instance ? Or do i have to take a dump and restore via mongodump/mongorestore ?
Thank you !!