Migrating from a Single Instance to a Cluster
Before migrating from a Single Instance to a Cluster, please read about Single Instance vs. Cluster
If you have developed your application using a Single Instance and you would like to use a Cluster now, before upgrading your production system please test your application with the Cluster first.
If both your Single Instance and Cluster are running on the same machine, they should have distinct data directories. It is not possible to start a Cluster on the data directory of a Single Instance.