Power Mode Configuration Guidelines - Cisco Nexus 9504 Hardware Installation Manual

Power Mode Configuration Guidelines

Power Mode Configuration Guidelines
The amounts of available and reserve power depend on the power redundancy mode that you specify and the
number of power supplies installed in the switch. For each redundancy mode, consider the following:
Combined mode
Cisco Nexus 9504 NX-OS Mode Switch Hardware Installation Guide
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The available power equals the combined output of all installed power supplies. There is no reserve
power. You activate this mode by using the power redundancy-mode combined command.
For example, if the power requirement for a switch is 5.2 kW and the switch has one 3-kW power
supply with 220 V input and 3.0-kW output, consider the following power planning scenarios:
• Scenario 1—No added power supplies
If you do not add a power supply unit, the available power (3.0 kW) is insufficient for the switch
power requirement of 5.2 kW, so the switch powers the supervisor modules, system controllers,
fan trays, and at least one fabric module before powering as many of the fabric and I/O modules
as the remaining available power can support (one or more fabric or I/O modules might not be
powered).
• Scenario 2—Install an extra 3-kW power supply
If you install an additional 3-kW power supply unit that can output 3.0 kW, the available power
becomes 6.0 kW. The increased amount of available power exceeds the switch power requirement
of 5.2 kW, so all of the modules and fan trays in the switch can power up.
The following table shows the results for each scenario.
Scenario Power Power
Requirement Supply 1
Output
1 5.2 kW 3.0 kW
2 5.2 kW 3.0 kW
Power Available Reserve
Supply 2 Power Power
Output
— 3.0 kW —
3.0 kW 6.0 kW —
Managing the Switch
Result
Available power is less
than the power
requirement for the
switch, so you cannot
power the entire switch
(some of the I/O modules
will not be able to power
up).
Available power exceeds
the power requirement
for the switch, so the
entire switch can power
up.