sub-cluster automatically. The CFS sub-clusters are formed automatically when the cluster starts. The SG SMS commands, CFS commands, and other utilities operate on the CFS sub-cluster where they are executed. The CFS sub-clusters manage the cluster file systems on disk arrays that are local to a site.

NOTE: The CFS sub-cluster functionality is supported only in a Metrocluster environment with sites defined in the underlying cluster.

Complex Workload Redundant Configuration

A complex workload is a multi-instance application that uses active resources across multiple nodes in a cluster. These workloads are configured using multiple, inter-dependent multi-node packages or failover packages in Serviceguard. The workloads need to be managed and moved collectively for disaster tolerance.

For SADTA, the complex workload is configured redundantly in the cluster. A separate set of packages must be used to configure the complex workload at each site.

Figure 57 is an example of a complex workload comprising an Application Package, Oracle RAC database MNP and its corresponding CFS Mount Point and Disk Group MNP packages. The arrows in the figure indicate the package dependencies.

Figure 57 Complex Workload with Package Dependencies Configured

In this figure, the complex workload in the San Francisco site is configured with the following packages: SFO_Application_package, SFO_RAC_MNP, SFO_SG_CFS_MP, and SFO_SG_CFS_DG. For redundancy, these packages are configured at the San Jose site. So the packages at the San Jose site include SJC_Application_package, SJC_RAC_MNP, SJC_SG_CFS_MP, and SJC_SG_CFS_DG packages.

Figure 58 (page 341) shows a similar configuration with a Web Server.

340 Designing a Disaster Recovery Solution Using Site Aware Disaster Tolerant Architecture