The illustrations that follow show the typical disaster recovery setup before and after a disaster.

In the previous illustration, before the disaster, the primary host replicates its application data to the secondary host. In a disaster recovery environment, the cluster on the primary site provides data and services during normal operation; the cluster on the secondary site provides data and services if the primary cluster fails. Note that the primary and the secondary sites have clusters to make both the application and Volume Replicator highly available.

If a disaster, such as an earthquake, causes a failure at the primary site, a host on the secondary site can take over the role of the primary host to make the data accessible and restore the application services and data to users.