Symantec 5 manual About multiple nodes, About shared storage, Example of a four-node VCS cluster

14Introducing Veritas Cluster Server About VCS basics

Figure 1-1illustrates a typical VCS configuration of four nodes that are connected to shared storage.

Figure 1-1	Example of a four-node VCS cluster
Client workstation		Client workstation

Public network

VCS private network

VCS nodes

Shared storage

Client workstations receive service over the public network from applications running on VCS nodes. VCS monitors the nodes and their services. VCS nodes in the cluster communicate over a private network.

About multiple nodes

VCS runs in a replicated state on each node in the cluster. A private network enables the nodes to share identical state information about all resources. The private network also recognizes active nodes, the nodes that join or leave the cluster, and failed nodes. The private network requires two communication channels to guard against network partitions.

About shared storage

A VCS hardware configuration typically consists of multiple nodes that are connected to shared storage through I/O channels. Shared storage provides multiple systems with an access path to the same data. It also enables VCS to restart applications on alternate nodes when a node fails, which ensures high availability.

VCS nodes can only access physically-attached storage.

Figure 1-2illustrates the flexibility of VCS shared storage configurations.