Compaq ProLiant 6500 Compaq Parallel Database Cluster Model PDC/05000 for Orac - Page 33

Cluster Architecture 2-9 Every node on a SCSI bus must have a unique SCSI bus ID. Table 2-2 shows the SCSI bus address ID assignments for the MA8000/EMA12000 Storage Subsystem. Table 2-2 SCSI bus address ID assignments for the MA8000/EMA12000 Storage Subsystem SCSI Bus ID 0 - 5 6 7 8, 9 10 - 15 SCSI Bus Node Physical drives in disk enclosure Array controller B Array controller A EMUs in the controller enclosure Physical drives in disk enclosure Each disk enclosure has two internal SCSI buses, with each bus controlling half of the total available disk drive slots in the enclosure. The single-bus I/O module places all physical disk drives in the enclosure on a single bus of 12 devices. The dual-bus I/O module maintains two internal buses with seven physical disk drive slots on each bus. For more detailed information about SCSI bus addressing for the MA8000/EMA12000 Storage Subsystem, refer to the Compaq documentation provided with the storage subsystem. UltraSCSI Cables Compaq recommends using the shortest cable length possible to connect disk enclosures to the controller enclosure. The maximum supported cable length is 2 meters (6.6 ft). Refer to the documentation provided with your storage subsystem for further information. Using I/O Modules in the Controller Enclosure As Figure 2-1 shows, both array controllers (A and B) connect to six I/O modules in the controller enclosure. UltraSCSI cables are installed between these I/O modules in the controller enclosure and one I/O module in each disk enclosure.