IBM TotalStorage DS4500, User Manual

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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 DS4500 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
enclosure operates at 1 Gbps only, while the DS4000 EXP100 and DS4000
EXP710 storage expansion enclosures do not operate at 1 Gbps. The
DS4500 Storage Server does not support mixed drive loop speeds.
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: If you are intermixing FAStT EXP500s and DS4000 EXP700s, it is
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 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
cabling scheme.
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
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.
v The maximum Fibre Channel transfer speed in all the DS4500 Storage Server
drive-side mini hubs must be set to 1 Gbps.
Attention: If you change the DS4000 EXP700 storage expansion enclosure or
DS4500 Storage Server enclosure link speed setting, you must power-cycle the
storage server. See “Turning off the power” on page 23 and “Turning on the
power” on page 22 for the proper DS4000 configuration power-down and
power-up sequences. For more information, see the IBM TotalStorage DS4000
Hard Drive and Storage Expansion Enclosure Installation and Migration Guide .
If you intermix FAStT EXP500s and DS4000 EXP700s within a single drive loop,
see Table 8 for the possible combinations of FAStT EXP500 and DS4000 EXP700
storage expansion enclosures per drive loop.
Table 8. Possible combinations of FAStT EXP500 and DS4000 EXP700 storage expansion
enclosures per drive loop
Number of FAStT
EXP500 units
Number of DS4000
EXP700 units
Total number of
storage expansion
enclosures
Total number of
drives
0 8 8 112
1 7 8 108
2 6 8 104
3 6 9 114
Chapter 1. Introduction
15