IBM 7133 Series Service Manual

Larger Configurations for Models 010 and 500Four more disk drive modules can be added to the base configuration in one loop. For abalanced subsystem, however, it is recommended that the two groups of four disk drivemodules be connected in two separate loops, each of which is connected to a separatepair of connectors on the SSA adapter.J10 J91 2 3 4 5 6 7 8J6 J57133 unitUsing systemA1 A2 B1 B2For this, and all larger configurations of Models 010 and 500, three fan-and-power supplyassemblies must be present in the 7133 if redundant power and cooling for all the diskdrive modules is required.No improvement in performance is gained if the disk drive modules are moved to otherslots and connected in more than two loops by way of an additional SSA adapter.The cables are described in “SSA Cables” on page 1-43. The internal connections ofModel 010 are shown in “Model 010 Internal Connections” on page 1-17; those of Model500 are shown in “Model 500 Internal Connections” on page 1-20.For information about the rules for SSA loops, see the “Rules for SSA Loops” onpage 1-42.Chapter 1. Reference Information 1-45