Chapter 3. Cabling The Exp420; Enclosure Id Settings - IBM System Storage DS4000 EXP420 Installation, User And Maintenance Instructions

Storage expansion enclosure

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Chapter 3. Cabling the EXP420

After the storage expansion enclosure is installed in its permanent location, you

must cable it to hosts and other storage devices, depending on your hardware

configuration.

This chapter addresses the following cabling and configuration topics:

v "Enclosure ID settings "

The enclosure ID, comprised of a pair of seven-segment numbers (referred to x10

and x1 digits), is located on the back of each ESM next to the indicator lights. It

provides a unique identifier for each module in the storage subsystem. Each

storage expansion enclosure (including the DS4000 storage subsystems with

internal drive slots) in the DS4000 storage subsystem configuration must have a

unique storage enclosure ID in the DS4000 subsystem configuration. In addition,

the single digits (x1) of the Enclosure IDs of all enclosures (including the DS4000

storage subsystems with internal drive slots) in the redundant drive channel/loop

pair must be unique.

The DS4000 controller firmware and storage expansion enclosure ESM

automatically set the enclosure ID number. You can change the setting through the

storage management software if necessary. Both ESM enclosure ID numbers are

identical under normal operating conditions.

The allowable ranges for enclosure ID settings are 0-99. However, IBM

recommends that you do not set the enclosure ID to 00 or any number greater than

80 because DS4000 storage subsystem enclosure IDs are set in this range. In

addition, you must ensure that the single-digit (x1) of the enclosure ID for every

enclosure in a redundant drive loop pair is unique. (This also includes any storage

subsystem that has drives installed.)

Figure 22 on page 38 shows the enclosure ID.

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