VCS Cluster Components

Resources, attributes, and service groups are components integral to cluster functionality. For more information, see the VERITAS Cluster Server User's Guide.

Resources

Resources are hardware or software entities, such as disks, volumes, file system mount points, network interface cards (NICs), IP addresses, applications, and databases. Resources work together to provide a service to clients in a client/server environment. The bundled agents resource types are defined in the types.cf file by a collection of attributes. The VCS configuration file, main.cf, contains the values for the attributes of the resources. The main.cf file incorporates the resources listed in the types.cf by way of an include directive. The main.cf file also incorporates the VVR resource types, which are defined in the file VVRTypes.cf by way of an include directive.

Attributes

Attributes contain data regarding the cluster, nodes, service groups, resources, resource types, and agents. A specified value for a given attribute configures the resource to function in a specific way. By modifying the value of an attribute of a resource, you change the way the VCS agent manages the resource. Each attribute has a definition and a value. You define an attribute by specifying its data type and dimension. Attributes also have default values that are assigned when a value is not specified.

Service Groups

Service groups are comprised of related resources. When a service group is brought online, all the resources within the group are brought online.