Users Guide

• Server Based Power Management
• Disable AC Power Recovery
Power Conservation and Power Budget
CMC conserves power when the user-configured maximum power limit is reached. When the demand for power exceeds the user
configured System Input Power Cap, CMC reduces power to servers in reverse-priority order to free power for higher priority servers and
other modules in the chassis.
If all or multiple slots in the chassis are configured with the same priority level, CMC decreases power to servers in the order of increasing
slot number. For example, if the servers in slots 1 and 2 have the same priority level, the power for the server in slot 1 is decreased before
that of the server in slot 2.
NOTE: You can assign a priority level to each server in the chassis assigning a number from 1 through 9 for each server.
The default priority level for all servers is 1. The lower the number, the higher the priority level.
The power budget is limited to a maximum of whichever set of two PSUs that is the weakest. If you attempt to set an AC power budget
value that exceeds the System Input Power Cap value, CMC displays a message. The power budget is limited to 4800W.
Maximum Power Conservation Mode
This is enabled for Grid Redundancy or PSU Redundancy modes. CMC performs maximum power conservation when:
• Maximum conservation mode is enabled.
• An automated command line script, issued by a UPS device, enables maximum conservation mode.
In maximum power conservation mode, all servers start functioning at their minimum power levels, and all subsequent server power
allocation requests are denied. In this mode, the performance of powered on servers may be degraded. Additional servers cannot be
powered on, regardless of server priority.
The system is restored to full performance when the maximum conservation mode is cleared.
NOTE:
If the Maximum Power Conversation Mode (MPCM) is enabled on the chassis, all power requests from a blade
server are denied. The blade server is not powered on if there is any action in the iDRAC or blade server requiring the
host to start the power cycle.
Server Power Reduction to Maintain Power Budget
CMC reduces power allocations of low-priority servers, when additional power is required to maintain the system power consumption
within the user-configured System Input Power Cap. For example, when a new server is engaged, CMC may decrease power to low-
priority servers to allow more power for the new server. If the amount of power is still insufficient after reducing power allocations of the
lower priority servers, CMC lowers the performance of servers until sufficient power is freed to power the new server.
CMC reduces server power allocation in two cases:
• Overall power consumption exceeds the configurable System Input Power Cap.
• A power failure occurs in a non-redundant configuration.
110V PSUs AC Operation
By default, the 110V PSU AC Operation feature is available. However, a combination of 110V and 220V operation is not supported. If CMC
detects that both voltages are input, one voltage value is selected and those power supplies connected to the other voltage level are
turned off and indicated as not functioning.
Remote Logging
Power consumption can be reported to a remote syslog server. Total chassis power consumption, minimum, maximum, and average power
consumption over a collection period can be logged. For more information about enabling this feature and configuring the collection or
logging interval, see Managing and Monitoring Power.
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Managing and Monitoring Power