Viewing And Configuring Power Cap Policy - Dell iDRAC7 User Manual

If there is not enough power allocated, the blade server does not power on. If the blade has been allocated enough
power, the iDRAC7 turns on the system power.

Viewing and Configuring Power Cap Policy

When power cap policy is enabled, it enforces user-defined power limits for the system. If not, it uses the hardware
power protection policy that is implemented by default. This power protection policy is independent of the user defined
policy. The system performance is dynamically adjusted to maintain power consumption close to the specified
threshold.
Actual power consumption may be less for light workloads and momentarily may exceed the threshold until
performance adjustments are completed. For example, for a given system configuration, the Maximum Potential Power
Consumption is 700W and the Minimum Potential Power Consumption is 500W. You can specify and enable a Power
Budget Threshold to reduce consumption from its current 650W to 525W. From that point onwards, the system's
performance is dynamically adjusted to maintain power consumption so as to not exceed the user-specified threshold of
525W.
If the power cap value is set to be lower than the minimum recommended threshold, iDRAC7 may not be able maintain
the requested power cap.
You can specify the value in Watts, BTU/hr, or as a percentage (%) of the recommended maximum power limit.
When setting the power cap threshold in BTU/hr, the conversion to Watts is rounded to the nearest integer. When
reading the power cap threshold back, the Watts to BTU/hr conversion is again rounded in this manner. As a result, the
value written could be nominally different than the value read; for example, a threshold set to 600 BTU/hr will be read
back as 601 BTU/hr.
Configuring Power Cap Policy Using Web Interface
To view and configure the power policies:
1. In iDRAC7 Web interface, go to Overview → Server → Power/Thermal → Power Configuration → Power
Configuration . The Power Configuration page is displayed.
The Power Configuration page is displayed. The current power policy limit is displayed under the Currently Active
Power Cap Policy section.
2. Select Enable under iDRAC Power Cap Policy.
3. Under User-Defined Limits section, enter the maximum power limit in Watts and BTU/hr or the maximum % of
recommended system limit.
4. Click Apply to apply the values.
Configuring Power Cap Policy Using RACADM
To view and configure the current power cap values:
• Use the following objects with the config subcommand:
– cfgServerPowerCapWatts
– cfgServerPowerCapBTUhr
– cfgServerPowerCapPercent
– cfgServerPowerCapEnable
• Using the following objects with the set subcommand:
– System.Power.Cap.Enable
– System.Power.Cap.Watts
– System.Power.Cap.Btuhr
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