• CMC does not support automated power-down of a low-priority server to allow turning-on of a higher priority server; however,you can perform user-initiated turn-offs.• Changes to the PSU redundancy policy are limited by the number of PSUs in the chassis. You can select any of the two PSUredundancy configuration settings listed in Default Redundancy Configuration.New Server Engagement PolicyIf a new server that is turned on exceeds the power available for the chassis, CMC may decrease the power to the low-priorityservers. This could happen if the administrator has configured a power limit for the chassis that is below what would be required forfull power allocation to the servers, or if insufficient power is available in case higher power requirements by all servers in the chassis.If enough power cannot be freed by reducing the allocated power of the low-priority servers, the new server is not allowed to turnon.This occurs if the administrator had configured power limit for the chassis lower than the full power allocation to the servers or ifinsufficient power is available to servers requiring high power.The following table provides the actions taken by CMC, when a new server is powered on in the scenario described earlier.Table 37. CMC Response When a Server Power-On is AttemptedWorst Case Power is Available CMC Response Server Power OnYes No power conservation is required AllowedNo Perform power conservation:• Power required for new server is available• Power required for new server is not availableAllowedNot AllowedIf a PSU stops functioning, it results in a non-critical health state and a PSU failure event is generated. The removal of a PSU resultsin a PSU removal event.If either event results in a loss of redundancy, on the basis of power allocations, a loss of redundancy event is generated.If the subsequent power capacity or the user power capacity is greater than the server allocations, servers have degradedperformance or, in an extrement case, servers may be turned off. Both conditions are in reverse-priority order; that is, the low-priority servers are turned off first.The following table provides the firmware response to a PSU turnoff, or removal as it applies to various PSU redundancyconfigurations.Table 38. Chassis Impact from PSU Failure or RemovalPSUConfiguration Dynamic PSUEngagement Firmware ResponseGrid Redundancy Disabled CMC alerts you about loss of Grid redundancy.Power SupplyRedundancyDisabled CMC alerts you about loss of power supply redundancy.Grid Redundancy Enabled CMC alerts you about loss of Grid Redundancy. PSUs in standby mode (if any) are turned onto compensate for power budget lost from the PSU failure or removal.Power SupplyRedundancyEnabled CMC alerts you of loss of Power Supply Redundancy. PSUs in standby mode (if any) areturned on to compensate for power budget lost from PSU failure or removal.Power Supply and Redundancy Policy Changes in System Event LogChanges in the power supply state and power redundancy policy are recorded as events. Events related to the power supply thatrecord entries in the system event log (SEL) are power supply insertion and removal, power supply input insertion and removal, andpower supply output assertion and de-assertion.The following table lists the SEL entries that are related to power supply changes:160
