In online VM replication, the source DS-Client sends replication data of the source virtual machine directly to the destination DS-Client, which places the replicated snapshot/checkpoint into the replication target virtual machine on the destination server. The snapshot/checkpoint is then ready to be used for failover.

A VM replication set will perform online replication if the Initial replication option is not selected in the Specify replication set options page in the New Replication Set Wizard.