Recommendations

To determine whether to create SUNW.HAStorage resources within a data service resource group, consider the following criteria.

• In cases where a data-service resource group has a node list in which some of the nodes are not directly connected to the storage, you must configure SUNW.HAStorage resources in the resource group and set the dependency of the other data-service resources to the SUNW.HAStorage resource. This requirement coordinates the boot order between the storage and the data services.

• If your data service is disk intensive, such as the Sun Cluster HA for Oracle and Sun Cluster HA for NFS data services, add a SUNW.HAStorage resource to your data-service resource group, set the dependency of your data-service resources to the SUNW.HAStorage resource, and set AffinityOn to True. When you perform these steps, the resource groups and disk device groups are colocated on the same node.

• If your data service is not disk intensive-such as one that reads all its files at startup (for example, the Sun Cluster HA for DNS data service)-configuring the SUNW.HAStorage resource type is optional.

• If your cluster contains only two nodes, configuring the SUNW.HAStorage resource type is optional. However, if you plan to add nodes and run scalable services later on, you must configure the SUNW.HAStorage resource type when you perform these tasks. To prepare, you can set up the SUNW.HAStorage resource type now and add nodes to the node list later.

See the individual chapters on data services in this document for specific recommendations.

See "How to Set Up SUNW.HAStorage Resource Type for New Resources" for information about the relationship between disk device groups and resource groups. Additional details are in the SUNW.HAStorage(5) man page.