Compaq ProLiant 6400R Compaq Parallel Database Cluster Model PDC/05000 for Ora - Page 79

Cluster Planning 4-5 I MA8000/EMA12000 Storage Subsystems, each of which holds up to 72 disk drives. I Two dual-port HSG80 Array Controllers installed in each storage subsystem's controller enclosure. NOTE: For more information about redundant Fibre Channel Arbitrated Loops (FC-ALs) in a PDC/O5000, see Chapter 2, "Cluster Architecture." The Storage Hubs are available in two models: I Storage Hub 7 (7 ports) I Storage Hub 12 (12 ports) To determine which Storage Hub model is appropriate for a redundant FC-AL in your cluster, you need to know the following: I Whether you are implementing dual redundancy or quad redundancy in the redundant FC-AL. Dual redundancy requires two host adapters per node and two Storage Hubs. Quad redundancy requires four host adapters per node and four Storage Hubs. I Total number of host adapters in all nodes I Total number of array controller ports in all of the storage subsystems in the redundant FC-AL You will need enough Storage Hub ports to accommodate the connections from the host adapters to the Storage Hubs and from the Storage Hubs to the array controllers. The number of storage subsystems and shared disk drives used in a PDC/O5000 redundant FC-AL depends on the amount of shared storage space required by the database, the hardware RAID levels used on the shared storage disks, and the number and storage capacity of disk drives installed in the enclosures. Refer to "Raw Data Storage and Database Size" in this chapter for more details. NOTE: For improved I/O performance and cluster integrity, as you increase the number of nodes in a PDC/O5000, you should also increase the aggregate bandwidth of the shared storage subsystem by adding more or higher-capacity disk drives.