Compaq ProLiant 6500 Compaq Parallel Database Cluster Model PDC/O2000 for Orac - Page 73

Cluster Architecture 2-49 Table 2-6 Features of Active/Standby and Active/Active Configurations for Redundant Fibre Channel Arbitrated Loops continued I/O Path Configuration Advantage Disadvantage Active/active with two or more RA4000/RA4100 Arrays Provides a small but measurable improvement in I/O performance over the active/standby configuration because both Fibre Host Adapters in each node and both Storage Hubs or FC-AL Switches are simultaneously active. This improvement can be meaningful for customers with large cluster databases or high I/O transaction requirements. Provides better load balancing between the two Storage Hubs than the active/standby configuration. Both Storage Hubs or FC-AL Switches are connected to the same or equivalent numbers of both active and standby array controllers in the RA4000/RA4100 Arrays. Does not provide true cabling symmetry between Storage Hubs or FC-AL Switches and array controllers if you consistently configure the top or rightmost array controller as the active controller. Each Storage Hub or FC-AL Switch is cabled to top (active) array controllers in some RA4000/RA4100 Arrays and bottom (standby) controllers in others. You can achieve cabling symmetry if you configure the bottom array controller in some RA4000/RA4100 Arrays as active. However, this requires using Secure Path to configure the lower array controller as active if it is in standby mode.