IBM DS4500 manual Configuring the drive loops

Drive Loop A Fibre	Input	Output		Drive Loop B Fibre
Channel interface			Input	Channel interface
Cables				Cables
				Output
				Last DS4000 drive
				enclosure

Storage Expansion

Enclosures -

Group 1

First DS4000 drive

enclosure

Drive Loop A

Drive Loop B

DS4500 Storage

Subsystem

Drive minihub 1

Drive minihub 2

ds452min

Figure 8. Redundant drive loop cabling overview with two mini hubs in slots 1 and 2 — Not for use unless you meet

the requirements in the above Note

Configuring the drive loops

The procedure and illustrations in this section show how to connect one group of four storage expansion enclosures in a redundant drive loop. Instructions for how to connect a second group of four storage expansion enclosures in a redundant drive loop are also included in this procedure.

To complete this procedure, you will need two fiber-optic cables per storage expansion enclosure.

Attention: Handle and install fiber-optic cables properly to avoid degraded performance or loss of communications with devices. Do not overtighten the cable straps or bend the cables to a diameter of less than 76 mm (3 in.), or a radius less than 38 mm (1.5 in.).

1.Connect the first two storage expansion enclosures to drive loop A, as shown in Figure 9 on page 11.

Starting with the first storage expansion enclosure, connect a fiber-optic cable from the In port on the left environmental services module (ESM) board to the Out port on the left ESM board in the second (next) storage expansion enclosure.

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