IBM DS4500 manual Drive interface ports, Drive mini-hub ports

Drive interface ports

DS4500 Storage Subsystems use only redundant drive-loop configurations. Each drive mini hub connects to Controller A and Controller B and represents a single drive loop. The drive loops must be set up in pairs to support redundant drive loop configurations (two data paths per storage expansion enclosure). See Figure 4 for an illustration of the drive-side mini-hub interface ports.

Drive loop C and D for redundant loop 2

Drive loop A and B
for redundant loop 1	4	3	2	1

2 Gb/s	2 Gb/s	2 Gb/s	2 Gb/s
1 Gb/s	1 Gb/s	1 Gb/s	1 Gb/s
!	!	!	!

OUT OUT OUT OUT

IN IN IN IN

2 Gb/s

1 Gb/s

!

OUT

IN

2 Gb/s	2 Gb/s	2 Gb/s
1 Gb/s	1 Gb/s	1 Gb/s
!	!	!

OUT OUT OUT

IN IN IN

Drive mini-hub ports

Use one port on each mini hub to connect a drive loop cable

Figure 4. Drive mini-hub ports

Leave one port unoccupied for future upgrades

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The maximum number of storage expansion enclosures that can be connected per pair of redundant drive loops depends on the IBM DS4000 storage expansion enclosure models used. The following DS4000 storage expansion enclosure types are supported by the DS4500 Storage Subsystem:

vFAStT EXP500

vDS4000 EXP700

vDS4000 EXP710

vDS4000 EXP100

If the drives are configured using only DS4000 EXP700, EXP710, or EXP100 storage expansion enclosures, the DS4500 Storage Subsystem supports a maximum of 224 hard drives.

If the drives are configured using only FAStT EXP500 storage expansion enclosures, the DS4500 Storage Subsystem supports a maximum of 220 hard drives.

Attention: In order to attach DS4000 EXP100 or DS4000 EXP710 storage expansion enclosures to a DS4500 Storage Subsystem, the DS4500 Storage Subsystem controller firmware must be at version 06.xx.xx.xx or higher. In addition, you must purchase the FC/SATA Enclosure Intermix premium option to combine DS4000 EXP100s with DS4000 EXP700s or DS4000 EXP710s in the same DS4500 Storage Subsystem configuration.

Refer to the IBM TotalStorage DS4000 Hard Drive and Storage Expansion Enclosure Installation and Migration Guide for complete information on storage expansion enclosure support and intermixing requirements for the DS4500 Storage Subsystem.

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