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BladeSystem - General
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Power Capacity of Enclosure

Trusted Contributor

Power Capacity of Enclosure

Hiro had a power capacity question:






One of Japanese customer has enclosure installed 4x 2250W power supplies with N+N redundancy.

He does not use power capping.

If he installed 10 blades, OA showed Power Capacity is 4500W DC.

If he installed 12 blades, OA showed Power Capacity is 4822W DC.


2 questions:


1) Why Power Capacity exceed 4500W at 12 blades case?

   My understanding is maximum power capacity is 4500W at this case because of 2x 2250W.


2) I found message "OA: Server Power Reduction Mode - Enabled" and "OA: Server Power Reduction Mode - Disabled" in OA syslog.

   What does this message mean?




Monty got involved:




Since the initial launch of the c7000 in June of 2006, the Onboard Administrator (OA) has been designed to support powering on as many ProLiant servers as possible.


One of the original c-Class ProLiant server blade design features is the ability to cap the power consumption of each server.


The OA firmware takes advantage of this capability to extend the Power Capacity of the enclosure – if the Power Mode is set to AC Redundant.


The OA will issue an OA syslog message indicating “Server Power Reduction Mode”, followed by “- Enabled, Disabled, Activated or Deactivated” if it modifies the Power Capacity of the enclosure.


Enabled indicates the Power Capacity has been extended beyond half the total available power supply capacity.

Disabled indicates the Power Capacity has been returned to equal half the total available power supply capacity.

Activated indicates that one ‘side’ of the power supply AC inputs have failed – and the servers have been automatically power capped to prevent them from brownout.

Deactivated indicates that all the power supply AC inputs have returned to OK status – and the power cap has been automatically removed.


This OA capability is completely automatic if the Power Mode is set to AC Redundant with at least 4 power supplies installed – minimum of 2 power supplies installed and status OK per side.


If the Enclosure Dynamic Power Capping feature is enabled, then the OA actively manages the power consumption of all ProLiant server blades (that have the iLO Advanced or Select license) in the enclosure using the Dynamic Power Capping feature in the ProLiant server blades.  The latest OA firmware permits this feature to be enabled on both Power Mode AC Redundant or Power Supply Redundant.




Any other input or questions?