In a VVR environment, applications can only write to the Primary data volumes. When replication is active, the application cannot write to the Secondary data volumes. To start the applications on the Secondary, you must transfer the Primary role to the Secondary. After transferring the role, you can start the application on the new Primary.

VVR enables you to transfer the Primary role from a healthy or failed Primary using a single command. It also enables you to fail back to the original Primary using a simple set of commands.