Compaq ProLiant 6400R Compaq Parallel Database Cluster Model PDC/05000 for Ora - Page 133

Installation and Configuration 5-37 If you do not install the optional Large LUN utility on your cluster, there are two accepted methods for distributing LUNs for storagesets: I You can distribute eight LUNs between the same-numbered ports on both array controllers so that a total of 16 LUNs are assigned across all four controller ports in each storage subsystem. For example, assign LUNs 0 through 3 to array controller A port 1, LUNs 4 through 7 to array controller B port 1, LUNs 100 through 103 to array controller A port 2, and LUNs 104 through 107 to array controller B port 2. If array controller A fails in multibus failover mode, Secure Path automatically gives controller B control over I/O transfers for LUNs 0-3 on port 1 and LUNs 100-103 on port 2. I You can distribute eight LUNs across all four array controller ports. For example, assign LUNs 0 and 1 to array controller A port 1, LUNS 2 and 3 to array controller A port 2, LUNS 4 and 5 to array controller B port 1, and LUNs 6 and 7 to array controller B port 2. In this configuration, a single controller port can access all eight LUNs in the event of a path failure on the other three ports. If you do install the optional Large LUN utility on your cluster, then you must follow these guidelines: I Do not assign unit offsets to any connections. I Use unit identifiers D0 through D63. I Distribute the LUNs evenly across all four array controller ports. To load balance the storagesets between the two array controllers: 1. From the CLI window, enter the following command to obtain a list of all units defined in the storage subsystem: show units 2. Enter the following command to specify preferred_path for units: set unit# preferred=this_controller or set unit# preferred=other_controller