Compaq ProLiant 6500 Compaq Parallel Database Cluster Model PDC/O2000 for Orac - Page 31

Cluster Architecture 2-7 FC-AL Switches IMPORTANT: For detailed information about cascading two FC-AL Switches, refer to the latest Compaq StorageWorks documentation. This guide does not document cascaded configurations for the FC-AL Switch. FC-AL Switches can be installed between cluster nodes and shared storage subsystems in PDC/O2000 clusters to create redundant Fibre Channel Arbitrated Loops (FC-ALs). FC-AL Switches are used to connect the Fibre Host Adapters in a PDC/O2000's redundant FC-AL to the array controllers in the RA4000/RA4100 Arrays. Two or more FC-AL Switches or Storage Hubs are used in each redundant FC-AL. Using at least two FC-AL Switches provides fault tolerance and supports the redundant architecture described in "Redundant Fibre Channel Arbitrated Loops" in this chapter. The FC-AL Switch 8 supports eight ports. With the addition of the 3-port Expansion Module (PEM), the switch supports 11 ports. For further information, refer to the Compaq StorageWorks Fibre Channel Arbitrated Loop Switch (FC-AL Switch) User Guide. Storage Hubs Storage Hubs can also be installed between cluster nodes and shared storage subsystems in PDC/O2000 clusters to create redundant Fibre Channel Arbitrated Loops (FC-ALs). Storage Hubs are used to connect the Fibre Host Adapters in a PDC/O2000's redundant FC-AL to the array controllers in RA4000/RA4100 Arrays. Two or more Storage Hubs or FC-AL Switches are used in each redundant FC-AL. Using at least two Storage Hubs provides fault tolerance and supports the redundant architecture described in "Redundant Fibre Channel Arbitrated Loops" in this chapter. On each Storage Hub, one port is used by a Fibre Host Adapter in each node and one port is used to connect to one of the two array controllers in each RA4000/RA4100 Array.