How VCS replicated data clusters work

To understand how a replicated data cluster configuration works, let us take the example of an application configured in a VCS replicated data cluster. The configuration has two system zones:

The application is installed and configured on all nodes in the cluster. Application data is located on shared disks within each RDC site and is replicated across RDC site to ensure data concurrency. The application service group is online on a system in the current primary zone and is configured to fail over in the cluster.

Figure: A VCS replicated data cluster configuration depicts an application configured on a VCS replicated data cluster.

Figure: A VCS replicated data cluster configuration

A VCS replicated data cluster configuration

In the event of a system or application failure, VCS attempts to fail over the application service group to another system within the same RDC site. However, in the event that VCS fails to find a failover target node within the primary RDC site, VCS switches the service group to a node in the current secondary RDC site (zone 1).