Migration involves transferring a healthy Primary of a Replicated Data Set (RDS) to a Secondary when the application involved in replication is inactive. Migration of a Primary to a Secondary is useful when the Primary must be brought down for reasons such as maintenance or to make the application active on another node.

In the following illustration, the Primary seattle is replicating to the Secondary hosts london and tokyo.

In the following illustration, the Primary role has been migrated from seattle to london and the new Primary london is replicating to seattle and tokyo. If you had already created RLINKs between london and tokyo when setting up replication, you do not need to manually reconfigure the additional Secondary tokyo as a part of the RDS. It will automatically be added as a Secondary of the new Primary london.

The vradmin migrate command restores the original configuration if it fails on any of the hosts during its execution.

Before migrating the Primary role, the vradmin migrate command displays a warning and prompts the user to confirm whether or not all the applications using the Primary volumes are stopped. To skip this confirmation, use the -s option with the vradmin migrate command, which proves useful in scripts.