You must create a cluster pair between two corresponding clusters before volumes can be paired.
This API method creates and returns a volume pairing key that is used to create a volume pair. The key contains information that is used to establish communications between volumes.
This method uses the pairing key created with the StartVolumePairing API method to create a volume pair. Issue the CompleteVolumePairing API method with the volumeID and volumePairingKey parameters to the destination volume.