I am curious about this topic too. Only I am working with an on-premise cluster of three (3) mongoDB servers.
The question I have is about the cluster configuration (see with rs.conf()). Cluster A is going to have it’s list of cluster members when I back up Cluster A.
How will cluster B handle when I restore a cold-backup copy of the database? Will it attempt to connect to the cluster A servers when I boot it up because the configuration (see with rs.conf()) will point to cluster A since that is where it was backed up from.
Are there any links which discuss this topic of, essentially, “Moving” a database from an old cluster to a new one?