Implementing Hardware and Software Redundancy on Modular Switches
How to configure redundant power supplies

The following command is used to implement power supply redundancy:

Switch(config)#power redundancy-mode mode
  • Combined mode disables redundancy. The power available to the system is the combined power capability of both power supplies. The system powers up as many modules as the combined capacity allows. If one supply should fail and there is not enough power for all previously powered-up modules, the system powers down those modules for which there is not enough power.
  • Redundant mode enables redundancy. In a redundant configuration, the total power drawn is at no time greater than the capability of one supply. If one supply malfunctions, the other supply can take over the entire system load. During normal operation with two power supplies, each provides approximately half of the required power to the system. Load sharing and redundancy are enabled automatically; no software configuration is required.

The show power command displays the current state of modules and the total power available:

Switch#show power

Turn Off or Cycle a Power to Modules
Power to a given module can be removed using this command;

Switch(config)#no power enable module slot
NOTE:

When the no power enable module slot command is used to power down a module, the module configuration is not saved.

To turn power back on for a module that was previously powered down, issue this command:

witch(config)#power enable module slot

he power to a module can be cycled (reset). The power cycle will turn the module power off for 5 seconds and then back on. To power cycle a module, issue this command:

witch(config)#power cycle module slot