Power Supply Modes; Configuration Guidelines For Power Supplies - Cisco MDS 9000 Series Configuration Manual

Managing System Hardware

Power Supply Modes

Cisco MDS 9000 Series Multilayer Switches support different number and capabilities of power supplies.
The following describe the power modes that are available on the Cisco MDS 9000 Series Multilayer Switches.
Not all the power modes are available on all the Cisco MDS 9000 Series Multilayer Switches.
Note
You can configure one of the following power modes to either use the combined power provided by the
installed power supply units (no power redundancy) or to provide power redundancy when there is a power
loss:
• Combined mode—Uses the combined capacity of all power supplies. In case of power supply failure,
• Input-source (grid) redundancy mode—This mode allocates half of the power to available power and
• Power-supply (n+1) redundancy mode—This mode allocates one power supply as a reserve power
• Full redundancy mode—This mode provides both power-supply (n+1) and input-source (grid)
For more information on the power supply modes supported on your switch, see your switch's Hardware
Installation Guide.

Configuration Guidelines for Power Supplies

When configuring power supplies follow these guidelines:
• When power supplies with different capacities are installed in the switch, the total power available differs
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the entire switch can be shut down (depends on the power used) causing traffic disruption. This mode
is seldom used, except in cases where the switch has two low-power supply capacities but a higher power
usage.
the other half to reserve power. You must use a different power source for the active and reserve power
sources so that if the power source used for active power fails, the other power source used for the reserve
power can provide power for the switch.
supply in case an available power supply fails. The remaining power supplies are allocated for available
power. The reserve power supply must be at least as powerful as each power supply used for the available
power.
redundancies. As happens with the input-source redundancy mode, this mode allocates half of the power
supplies to provide available power and the other half of the power supplies to provide the reserve power.
One of the reserve power supplies can alternatively be used to provide power if a power supply supplying
the available power fails.
based on the configured mode, either redundant or combined:
◦Redundant mode—The total power is 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
Cisco MDS 9000 Family NX-OS Fundamentals Configuration Guide
Power Supply Modes
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