The following figure illustrates the failover DAS and failover Node Agent configuration before any node failure occurs.
The figure illustrates the following setup.
There are two physical nodes, Node1 and Node2.
The DAS is contained in the failover resource group RG1 on Node1 and listens on failover IP address IP1.
The Node Agent NA1 and the Application Server instances I1 and I2 that the Node Agent manages are contained in the resource group RG2 on Node1 and listen on failover IP address IP2.
The Node Agent NA2 and the Application Server instances I3 and I4 that the Node Agent manages are contained in the resource group RG3 on Node2 and listen on failover IP address IP3.
There is one domain, Domain1, which contains the DAS and the two Node Agents, as well as all the instances managed by the Node Agents.
The Application Server is installed on the global file system (GFS) and is accessible to the components on both Node1 and Node2.
Bringing these resource groups online starts the Node Agents, which in turn start the Application Server instances that they manage.