VERITAS Cluster Server

VCS functions as the director of operations for Storage Foundation for Oracle RAC. VCS controls startup and shutdown of the component layers of RAC. In the Storage Foundation for Oracle RAC configuration, the RAC service groups run as parallel service groups. VCS does not attempt to migrate a failed service group, but the software enables you to configure it to restart on failure. VCS also notifies users of any failures.

Storage Foundation for Oracle RAC provides specific agents for VCS to operate in a Storage Foundation for Oracle RAC environment, including CVM, CFS and Oracle.

VCS Architecture

VCS communicates the status of resources running on each system to all systems in the cluster. The High Availability Daemon (HAD) is the main VCS daemon running on each system. HAD collects all information about resources running on the local system and forwards it to all other systems in the cluster. This daemon also receives information from all other cluster members to update its own view of the cluster.

Each type of resource supported in a cluster is associated with an agent. An agent is an installed program designed to control a particular resource type. Each system runs necessary agents to monitor and manage resources configured to run on that node. The agents communicate with HAD on the node. HAD distributes its view of resources on the local node to other nodes in the cluster using GAB and LLT.

Storage Foundation for Oracle RAC Service Groups

Storage Foundation for Oracle RAC uses parallel service groups to support RAC. A single CVM group exists per server. This group has the CVM resource and the necessary resources to support CFS. Users can modify this group to contain all common components needed by Oracle to support RAC. These components include a shared ORACLE_HOME directory and the Oracle Net Services process (LISTENER).

Users create a service group for each Oracle database on shared storage, specifying the supporting CVM and CFS resources.

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