The DNS associates a client with the logical hostname of an application. After a failover or switchover, the DNS mapping to the primary cluster must be removed, and a DNS mapping to the secondary cluster must be created. The following figure shows how the DNS maps a client to a cluster.
To update the DNS, use the nsupdate command. For information, see the nsupdate(1M) man page. For an example of how to manage a failover or switchover, see Example of How to Manage a Failover or Switchover.
Synchronize the primary cluster with the secondary cluster to ensure that the primary volume is up-to-date.
Update the DNS so that clients can access the application on the primary cluster.