The following table lists important terms used in the Power Management process.
Term |
Definition |
---|---|
PSU |
Power Supply Unit |
Energized PSU |
A PSU supplying DC power |
Available PSU Count |
The number of PSUs assigned to deliver Available Power to the chassis. |
Reserve PSU Count |
The number of PSUs assigned to deliver standby power to the chassis. |
Power |
The DC power supplied to the chassis by a PSU |
Total Power |
The Power supplied to the chassis components and blades by all energized PSUs. Total Power is equal to the sum of Available Power plus Reserve Power. |
Available Power |
A power management metric. Available Power is the portion of Total Power that is currently available to chassis components and blades. The Chassis Monitoring Module (CMM) allocates the amount of Available Power when the chassis is powered on. This power allocation is based on the number of energized PSUs providing power. |
Reserve Power |
A power management metric. Reserve Power is the portion of Total Power that is being reserved for chassis components and blades. Reserve Power can be allocated at any time without adversely impacting the power requirements of the chassis. |
Ticketed Power |
A power management metric. Ticketed Power is the amount of Available Power that is set for allocation to a specific chassis component or blade. Ticketed Power is a portion of Available Power, but could include a portion of Reserve Power. |
Consumed Power |
A power management metric. Consumed Power is the portion of Total Power that is being used by the entire chassis, or by a specific chassis component such as a blade server. |
Power Budget Ticketing Protocol |
Process through which a blade service processor (SP) must request permission from the CMM to enable blade power-on. Permission is granted based on the maximum power requirements of the blade and Available Power in the chassis. |
Blade Ticketed Power |
The portion of the chassis Ticketed Power that is reserved for a blade. |
Blade Consumed Power |
The fraction of Consumed Power that is being consumed by that blade at a specific point in time. |
Oversubscription |
The condition where the chassis Ticketed Power exceeds that chassis Available Power. |
Critical Oversubscription |
The condition where the chassis Consumed Power exceeds the chassis Total Power. There is a danger of a "brown out" when in this condition. |
Brown Out |
The chassis experiences an over-current power failure and shuts down. |