Before you configure data services to use the controls provided by Solaris in a Sun Cluster environment, you must decide how you want to control and track resources across switchovers or failovers. Consider identifying dependencies within your cluster before configuring a new project. For example, resources and resource groups depend on disk device groups. Use the nodelist, failback, maximum_primaries and desired_primaries resource group properties, configured with scrgadm(1M) to identify nodelist priorities for your resource group. Refer to “scrgadm” in Sun Cluster 3.1 Data Service Planning and Administration Guide for a brief discussion of the node list dependencies between resource groups and disk device groups. For detailed property descriptions, refer to rg_properties(5).
Use the preferenced and failback properties configured with scrgadm(1M) and scsetup(1M) to determine disk device group nodelist priorities. For procedural information, see “How To Change Disk Device Properties” in “Administering Disk Device Groups” in Sun Cluster 3.1 System Administration Guide. Refer to Failover and Scalability in the SunPlex System for conceptual information about node configuration and the behavior of failover and scalable data services.
If you configure all cluster nodes identically, usage limits are enforced identically on primary and secondary nodes. The configuration parameters of projects need not be identical for all applications in the configuration files on all nodes. All projects associated with the application must at least be accessible by the project database on all potential masters of that application. Suppose that Application 1 is mastered by phys-schost-1 but could potentially be switched over or failed over to phys-schost-2 or phys-schost-3. The project associated with Application 1 must be accessible on all three nodes (phys-schost-1, phys-schost-2, and phys-schost-3).
Project database information can be a local /etc/project database file or may be stored in the NIS map or the LDAP directory service.
The Solaris environment allows for flexible configuration of usage parameters, and few restrictions are imposed by Sun Cluster. Configuration choices depend on the needs of the site. Consider the general guidelines in the following sections before configuring your systems.