HP Cisco MDS 9216 - Fabric Switch Configuration Manual page 350

Power Supply Configuration Modes
S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
Table 18-1
Scenario
2
3
1. W = Watts
Table 18-2
Scenario
1
2
3
1. W = Watts
When you change the configuration from combined to redundant mode and the system detects a
2.
power supply that has a capacity lower than the current usage, the power supply is shut down. If both
power supplies have a lower capacity than the current system usage, the configuration is not allowed.
Several configuration scenarios are summarized in
Scenario 1: You have the following usage figures configured:
Cisco MDS 9000 Family CLI Configuration Guide
18-6
Redundant Mode Power Supply Scenarios (continued)
Power Current
Supply 1 Usage
1
(W) (W)
2500 2000
2500 2000
b. 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 differ as specified (see
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).
Combined Mode Power Supply Scenarios
Power Current
Supply 1 Usage
1
(W) (W)
2500 2000
2500 2000
2500 2000
Power supply 1 = 2500 W
Additional Power supply 2 = 1800 W
Current Usage = 2000 W
Current mode = combined mode (so current capacity is 3600 W)
You decide to change the switch to redundant mode. Then power supply 2 is shut down.
Insertion of New
Power Capacity
Supply 2 (W) (W)
2200 2200
3300 2500
Insertion of New
Power Capacity
Supply 2 (W) (W)
1800 3600
2200 4400
3300 5000
Table 18-3.
OL-16184-01, Cisco MDS SAN-OS Release 3.x
Chapter 18 Managing System Hardware
Action Taken by Switch
Capacity becomes 2200 W.
Capacity remains the same.
Table 18-2):
Action Taken by Switch
Power is never shut down. The
new capacity is changed.