Cisco MDS 9000 Series Configuration Manual page 164

Configuration Guidelines for Power Supplies
Cisco MDS 9000 Family NX-OS Fundamentals Configuration Guide
146
Then the following three scenarios will differ as specified:
Scenario 1: If 1800 W is added as power supply 2, then power supply 2 is
shut down.
Reason: 1800 W is less than the usage of 2000 W.
Scenario 2: If 2200 W is added as power supply 2, then the current capacity
decreases to 2200 W.
Reason: 2200 W is the lesser of the two power supplies.
Scenario 3: If 3000 W is added as power supply 2, then the current capacity
value remains at 2500 W.
Reason: 2500 W is the lesser of the two power supplies.
This table describes the actions for the scenarios.
Table 19: Redundant Mode Power Supply Scenarios
Scenario Power Supply
1 (Watts)
1 2500
2 2500
3 2500
◦Combined mode—The total power is twice the lesser of the two power supply capacities.
For example, suppose you have the following usage figures configured:
Power supply 1 = 2500 W
Additional Power supply 2 = not used
Current Usage = 2000 W
Current capacity = 2500 W
Then the following three scenarios will differ as specified:
Scenario 1: If 1800 W is added as power supply 2, then the capacity
increases to 3600 W.
Reason: 3600 W is twice the minimum (1800 W).
Scenario 2: If 2200 W is added as power supply 2, then the current
capacity increases to 4400 W.
Reason: 4400 W is twice the minimum (2200 W).
Scenario 3: If 3000 W is added as power supply 2, then the current
capacity increases to 5000 W.
Reason: 5000 W is twice the minimum (2500 W).
This table describes how these scenarios differ.
Current Usage Insertion of
(Watts) Power Supply
2 (Watts)
2000 1800
2000 2200
2000 3300
Managing System Hardware
New Capacity Action Taken
(Watts) by Switch
2500 Power supply
2 is shut
down.
2200 Capacity
becomes 2200
W.
2500 Capacity
remains the
same.
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