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18-7
Cisco MDS 9000 Family Fabric Manager Configuration Guide
OL-17256-03, Cisco MDS NX-OS Release 4.x
Chapter 18 Managing System Hardware
About Crossbar Management
Reason: 1800 W is the lesser of the two power supplies and it is less than the system usage.
Scenario 2: You have the following usage figures configured:
Power supply 1 = 2500 W
Additional Power supply 2 = 2200 W
Current Usage = 2000 W
Current mode = combined mode (so current capacity is 4400 W).
You decide to change the switch to redundant mode. Then the current capacity decreases to
2200 W.
Reason: 2200 W is the lesser of the two power supplies.
Scenario 3: You have the following usage figures configured:
Power supply 1 = 2500 W
Additional Power supply 2 = 1800 W
Current Usage = 3000 W
Current mode = combined mode (so current capacity is 3600 W).
You decide to change the switch to redundant mode. Then the current capacity decreases to
2500 W and the configuration is rejected.
Reason: 2500 W is less than the system usage (3000 W).
About Crossbar Management
Cisco MDS NX-OS Release 4.1(1b) and later supports three types of hardware for the Cisco MDS 9500
Series Directors: Generation 1, Generation 2, and Generation 3.
Generation 3 consists of hardware supported by Cisco NX-OS Release 4.1(1b) and later, including the
following:
• 48-port 8-Gbps Fibre Channel switching module
• 24-port 8-Gbps Fibre Channel switching module
• 4/44-port 8-Gbps Host Optimized Fibre Channel module
Table 18-3 Combined Mode Power Supply Scenarios
Scenario
Power
Supply 1 (W)
1
1. W = Watts
Current
Mode
Current
Usage (W)
Power
Supply 2 (W) New Mode
New
Capacity (W) Action Taken by Switch
1 2500 combined 2000 1800 N/A 3600 This is the existing
configuration.
2500 N/A 2000 1800 redundant 2500 Power supply 2 is shut down.
2 2500 combined 2000 2200 N/A 4400 This is the existing
configuration.
2500 N/A 2000 2200 redundant 2200 The new capacity is changed.
3 2500 combined 3000 1800 N/A 3600 This is the existing
configuration.
2500 N/A 3000 1800 redundant N/A Rejected, so the mode reverts
to combined mode.