Convert a Standalone to a Replica Set
The procedure is specific to instances that are not part of a sharded cluster. To convert a shard standalone instance to a shard replica set, see Convert a Shard Standalone to a Shard Replica Set instead.
To install a standalone instance, see the installation tutorials.
Restart the instance. Use the --replSet option to specify the name of the new replica set.
For example, the following command starts a standalone instance as a member of a new replica set named
rs0 . The command uses the standalone’s existing database path of
mongod --port 27017 --dbpath /srv/mongodb/db0 --replSet rs0 --bind_ip localhost,<ip address of the mongod host>
If your application connects to more than one replica set, each set should have a distinct name. Some drivers group replica set connections by replica set name.