Ds4000 Storage Expansion Enclosure Support; Redundant Host-Side Fibre Channel Cabling - IBM DS4800 Installation And Cabling Manual

The following figure shows the recommended redundant cabling topology for attaching a single DS4000
storage expansion enclosure to the DS4800. The topology shown uses ports from drive channels 1 (on
EXP710 controller A) and 3 (on controller B) to achieve a redundant connection to the DS4000 enclosure
Figure 3. Recommended cabling for a single DS4000 storage expansion enclosure to the DS4800

DS4000 storage expansion enclosure support

The DS4800 supports a maximum of 224 drives in two redundant drive channel pairs. The DS4800
storage subsystem enables you to mix certain storage expansion enclosure models in the same
configuration. In some cases, to intermix storage expansion enclosure models you must meet additional
requirements, such as firmware updates or grouping restrictions. To intermix fibre channel and SATA
drives, you must purchase the FC/SATA Enclosure Intermix premium feature. Refer to the IBM System
Storage DS4000 Hard Drive and Storage Expansion Enclosure Installation and Migration Guide for complete
information on enclosure support and intermixing requirements for the DS4800 storage subsystem.

Redundant host-side fibre channel cabling

The DS4800 supports redundant connections to up to four hosts. To ensure full protection against the loss
of any one fibre channel path from the host servers to the DS4800 storage subsystem, always use
redundant host connections by connecting each host to the appropriate single-ported host channels on
both RAID controllers A and B.
To connect the first host server to the DS4800, connect one host server FC host adapter to host
1.
channel 1 of controller A (top), and connect the other host server FC host adapter to host channel 1 of
controller B (bottom).
2. To connect additional redundant hosts, connect the two host server FC host adapters to the next host
channels on each controller (A and B), as shown in Figure 4 on page 5.
4
Controller A
Controller B
1 Gb/s 2 Gb/s
X10 X1
Conflict
Tray Number
Drive Channel 1
Drive Channel 3
DS4800
Storage
Subsystem
DS4000
Storage
Expansion
Enclosure