Intermixing Storage Expansion Enclosure Models - IBM TotalStorage DS4400 User Manual

If the drives are configured using only DS4000 EXP700, EXP710, or EXP100
storage expansion enclosures, the DS4400 Storage Server supports a maximum of
224 hard drives.
If the drives are configured using only FAStT EXP500 storage expansion
enclosures, the DS4400 Storage Server supports a maximum of 220 hard drives.
Attention:
expansion enclosures to a DS4400 Storage Server, the DS4400 Storage Server
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 DS4400 Storage
Server configuration.
For detailed information about how to cable the storage server and storage
expansion enclosures, see the IBM TotalStorage DS4400 Fibre Channel Storage
Server Installation and Support Guide and the DS4400 Fibre Channel Cabling
Instructions that come with the storage server.

Intermixing storage expansion enclosure models

Storage expansion enclosure models can be mixed in the same redundant drive
loop or the same pair of redundant drive loops. As described in the following
sections, you can intermix FAStT EXP500s and DS4000 EXP700s, and you can
also intermix DS4000 EXP100s, EXP710s, and EXP700s.
You cannot mix DS4000 EXP100s or DS4000 EXP710s with FAStT EXP500s in any
DS4000 storage server configuration. If a DS4000 EXP100 or DS4000 EXP710 is
attached to the DS4400 Storage Server in one drive loop, no FAStT EXP500s can
be present either in the same drive loop or in the other drive loop.
Note: This restriction exists because the FAStT EXP500 storage expansion
Intermixing FAStT EXP500s and DS4000 EXP700s: You can intermix FAStT
EXP500 and DS4000 EXP700 storage expansion enclosure models in the same
redundant pair of drive loops.
Attention:
strongly recommended that you do not cable the FAStT EXP500 and DS4000
EXP700 storage expansion enclosure models in the same redundant drive loop
pair. Instead, you should cable the FAStT EXP500 storage expansion enclosures
together using one pair of redundant drive loops, and you should cable the DS4000
EXP700 storage expansion enclosures together using the other pair of redundant
drive loops.
Note: You might need to purchase two additional drive mini-hubs to implement this
If you are intermixing FAStT EXP500s and DS4000 EXP700s, your drive loop
configuration must meet the following requirements:
v The maximum Fibre Channel transfer speed in all of the DS4000 EXP700s must
16
IBM TotalStorage DS4400 Fibre Channel Storage Server: User's Guide
In order to attach DS4000 EXP100 or DS4000 EXP710 storage
enclosure operates at 1 Gbps only, while the DS4000 EXP100 and DS4000
EXP710 storage expansion enclosures do not operate at 1 Gbps. The
DS4400 Storage Server does not support mixed drive loop speeds.
If you are intermixing FAStT EXP500s and DS4000 EXP700s, it is
cabling scheme.
be set to 1 Gbps because the maximum FC transfer speed of the IBM FAStT
EXP500 storage expansion enclosures is 1 Gbps. Otherwise, a drive channel
mini-hub data rate mismatch error will be generated.