Cisco Systems OL-25712-04 Configuring Policy-Driven Chassis Group Power Capping

Anychange to the manual blade-level power cap configuration will result in the loss of any groups or

configurationoptions set forpolicy-driven chassis group power capping.

Important

Procedure

Step 1 Inthe Navigation pane, clickthe Equipmenttab.

Step 2 Onthe Equipment tab, click the Equipment node.

Step 3 Inthe Work pane, click the Policies tab.

Step 4 Clickthe Global Policiessubtab.

Step 5 Inthe Global Cap Policy area, clickone of the following radio buttons in the Allocation Method field to

determinethe power cap management mode used in the Cisco UCS domain:

•ManualBlade Level Cap—Power allocation is configured on each individual blade server in all chassis.

Ifyou select this option, you cannot create power groups.

•PolicyDriven Chassis Group Cap—Power allocation is configured at the chassis level through power

controlpolicies included in the associated service profiles. If you select this option, you can also create

powergroups thatcontain one or more chassis in the Cisco UCS domain.

Bydefault, power allocation is done for each chassis through a power control policy.

Step 6 ClickSave Changes.

Configuring Policy-Driven Chassis Group Power Capping

Whenpolicy-driven power chassis group power capping is selected in the global cap policy, Cisco UCS can

maintainthe oversubscription of servers without risking costly power failures. This is achieved through a

two-tierprocess. At the chassis level, Cisco UCS divides the amount of power available between members

ofthe power group. At the blade level, the amountof power allottedto a chassisis divided betweenblades

basedon priority.

Eachtime a service profile isassociated or disassociated, UCS Manager recalculates the power allotmentfor

eachblade server withinthe chassis.If necessary,power from lower-priority service profiles is redistributed

tohigher-priority service profiles.

UCSpower groups cap power in less than one second in order to safely protect data center circuit breakers.

Ablade must stay at its cap for 20 seconds before the chassis power distributionis optimized. This is

intentionallycarried out over a slower timescale to prevent reacting to transient spikes in demand.

Cisco UCS Manager GUI Configuration Guide, Release 2.0

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Configuring Policy-Driven Chassis Group Power Capping