Power management

To set the power management options in Onboard Administrator, go to the menu on the left and select the enclosure to be managed. Click Power and Thermal>Power Management. The main Power Management page appears and displays the following choices:

AC Redundant
Power Supply Redundant
Not Redundant

Beneath the main power management choices is the Dynamic Power Savings mode checkbox which allows you to enable Dynamic Power Savings Mode.

The AC Input VA Limit field enables you to set a VA limit for the enclosure. After this limit is met by the enclosure, it will not allow any further blades, power supplies, fans, or switches to power on. If a value is entered into the VA Limit field that is lower than the currently used VA for the enclosure, the enclosure will not power off any devices within the enclosure. However, if a device is powered off, it cannot power on because of the VA limit rule set in the Onboard Administrator power management settings.

IMPORTANT: If redundancy mode is set to Redundant, AC Redundant, or Power Supply Redundant, and power redundancy is lost, then you must either add additional power supplies or change the redundancy mode setting in the Onboard Administrator to restore Power Subsystem status. See the Insight Display for corrective steps.

IMPORTANT: To change the power redundancy mode, you must disable EDPC. After changing the power redundancy mode, reset EDPC based on the new ranges.

The HP BladeSystem c3000 or c7000 Enclosure power management system enables you to configure the enclosure to meet your needs. You can choose from the different modes on the Onboard Administrator Power Management screen. The power modes are explained in the following table.

Power Mode

Mode	Insight Display name	Description
Redundant	Redundant	For DC power supplies only. In this configuration, N power supplies are used to provide power and N are used to provide redundancy (where N can equal 1, 2, or 3). Up to three power supplies can fail without causing the enclosure to fail. When correctly wired with redundant DC line feeds, this configuration also ensures that a DC line feed failure does not cause the enclosure to power off.
AC Redundant	AC Redundant	For AC power supplies only. In this configuration, N power supplies are used to provide power, and N are used to provide redundancy (where N can equal 1, 2, or 3). Up to three power supplies can fail without causing the enclosure to fail. When correctly wired with redundant AC line feeds, this configuration also ensures that an AC line feed failure does not cause the enclosure to power off.
Power Supply Redundant	Power Supply	Up to six power supplies can be installed with one power supply always reserved to provide redundancy. In the event of a single power supply failure, the redundant power supply takes over the load. A line feed failure of more than one power supply causes the system to power off.
Not Redundant	None	There is no power redundancy and no power redundancy warnings are given. If all power supplies are needed to supply Present Power, then any power supply or line failure may cause the enclosure to brown-out.

Dynamic Power

Mode	Insight Display name	Description
Dynamic Power	Dynamic Power	If enabled, Dynamic Power automatically places unused power supplies in standby mode to increase enclosure power supply efficiency, thereby minimizing enclosure power consumption during lower power demand. Increased power demands automatically return standby power supplies to full performance. This mode is not supported for low voltage on the c7000 enclosure.

The default setting is Enabled. The following selections are valid:

Enabled—Some power supplies can be automatically placed on standby to increase overall enclosure power subsystem efficiency.
Disabled—All power supplies share the load. The power subsystem efficiency varies based on load.

Power Limit

Do not set a Static Power Limit or Enclosure Dynamic Power Cap on an empty enclosure.

Mode	Insight Display name	Description
Enclosure Dynamic Power Cap	None	An optional feature that enables you to cap the servers in an enclosure as a group. As the servers run, the demand for power varies for each server. A power cap for each server is automatically adjusted to provide the server with enough power to meet workload demands while still conforming to the Enclosure Dynamic Power Cap. The feature is enabled with three configuration parameters: Dynamic Power Cap—Total enclosure average power will not exceed Dynamic Power Cap. Derated Circuit Capacity—Average power on a single circuit will not exceed Derated Circuit Capacity. Rated Circuit Capacity—Peak power on a single circuit will not exceed Rated Circuit Capacity. When configuring these parameters, the Derated Circuit Capacity must be at least as large as the Dynamic Power Cap and no larger than the Rated Circuit Capacity. The Dynamic Power Cap is used to limit the enclosure power consumption based on a cooling constraint that might be lower than the Derated Circuit Capacity. The Derated Circuit Capacity is used to limit the enclosure average power consumption on a circuit. The Rated Circuit Capacity is used to limit the enclosure peak power consumption on a circuit. If you need to restrict an enclosure electrical load and thermal output, an Enclosure Dynamic Power Cap is better than a Static Power Limit. Enclosure Dynamic Power Cap enables more blades to power on than a Static Power Limit. For a complete list of BladeSystem server blades supported by Enclosure Dynamic Power Capping, see the HP website.
Static Power Limit	Power Limit	An optional setting to limit power. Whenever you attempt to power on a device, the total power demands of the new device and of the devices already on are compared against this Static Power Limit. If the total power demands exceed the limit, the new device is prevented from powering on. A Static Power Limit is better when: You do not want caps dynamically adjusted on your blades. You prefer to not power on a server blade if it cannot be allocated full power (even if it typically consumes less). More than 1/4 of the blades in the enclosure do not meet hardware or firmware requirements for the Enclosure Dynamic Power Cap.
None	None	The enclosure power usage is not managed or capped.

Mode

Insight Display name

Description

Enclosure Dynamic Power Cap

None

An optional feature that enables you to cap the servers in an enclosure as a group. As the servers run, the demand for power varies for each server. A power cap for each server is automatically adjusted to provide the server with enough power to meet workload demands while still conforming to the Enclosure Dynamic Power Cap.

The feature is enabled with three configuration parameters:

Dynamic Power Cap—Total enclosure average power will not exceed Dynamic Power Cap.
Derated Circuit Capacity—Average power on a single circuit will not exceed Derated Circuit Capacity.
Rated Circuit Capacity—Peak power on a single circuit will not exceed Rated Circuit Capacity.
When configuring these parameters, the Derated Circuit Capacity must be at least as large as the Dynamic Power Cap and no larger than the Rated Circuit Capacity.
The Dynamic Power Cap is used to limit the enclosure power consumption based on a cooling constraint that might be lower than the Derated Circuit Capacity. The Derated Circuit Capacity is used to limit the enclosure average power consumption on a circuit. The Rated Circuit Capacity is used to limit the enclosure peak power consumption on a circuit.
If you need to restrict an enclosure electrical load and thermal output, an Enclosure Dynamic Power Cap is better than a Static Power Limit. Enclosure Dynamic Power Cap enables more blades to power on than a Static Power Limit.
For a complete list of BladeSystem server blades supported by Enclosure Dynamic Power Capping, see the HP website.

Static Power Limit

Power Limit

An optional setting to limit power. Whenever you attempt to power on a device, the total power demands of the new device and of the devices already on are compared against this Static Power Limit. If the total power demands exceed the limit, the new device is prevented from powering on.

A Static Power Limit is better when:

You do not want caps dynamically adjusted on your blades.
You prefer to not power on a server blade if it cannot be allocated full power (even if it typically consumes less).
More than 1/4 of the blades in the enclosure do not meet hardware or firmware requirements for the Enclosure Dynamic Power Cap.

None

The enclosure power usage is not managed or capped.

Understanding Power Capping, Dynamic Power Capping, and Enclosure Dynamic Power Capping

HP delivers three varieties of power management that allows users to limit the server power consumption. All three power capping varieties work to limit consumption to a specified Watt or Btu/hr goal. The three technologies are Power Capping, Dynamic Power Capping, and EDPC.

Power Capping

HP launched Power Capping technology in May of 2007 with iLO version 1.30. This firmware-based technology limits the average power consumption of the server to a user-defined Watt or Btu/hr goal. Because this technology runs in firmware, it cannot limit power consumption rapidly enough to ensure protection of PDU-level circuit breakers. Power Capping does limit power consumption rapidly enough to protect cooling infrastructure, so it is an effective solution for data centers experiencing cooling capacity constraints. Power Capping is supported on any ProLiant server or blade that has an iLO management processor and power measurement capabilities. Using Power Capping requires iLO version 1.30 (or later) firmware and an updated system ROM/BIOS.

Dynamic Power Capping

Dynamic Power Capping is a hardware-based technology that limits power consumption fast enough to protect circuit breakers and cooling infrastructure. HP launched Dynamic Power Capping in December of 2008 with iLO version 1.70. Supported servers contain an internal hardware circuit that monitors server power consumption on a sub-second basis. If server power consumption approaches the power cap limit set in iLO, the internal hardware circuit limits power consumption rapidly enough to protect PDU-level circuits from over-subscription and prevent power-related server outages.

Dynamic Power Capping requires specific hardware on the system board. Dynamic Power Capping also requires iLO version 1.70 (or later) firmware and a system ROM/BIOS dated 10/1/2008 (or later). iLO automatically updates firmware in the Dynamic Power Capping hardware power circuit.

Enclosure Dynamic Power Capping

EDPC combines the power capping technology of the BladeSystem server with a power balancing control algorithm in the Onboard Administrator to maximize the aggregate performance of the enclosure. EDPC protects circuit breakers and maximizes performance.

Use EDPC to set a power cap for the entire enclosure. The Onboard Administrator intelligently allocates individual limits to each participating server blade. The server blades manage their consumption to that limit. The Onboard Administrator continuously monitors power consumption requirements for each server blade and continuously balances the individual limits to ensure that busy server blades receive more power than idle server blades. This power allocation improves aggregate enclosure performance.

BladeSystem servers should have their power cap set in the Onboard Administrator. EDPC protects both cooling and electrical infrastructures. EDPC works with either firmware-based power capping technology on the server or with the fast, hardware-based technology. The EDPC solution performs better if the server blades that support the fast, hardware-based capping technology are upgraded.

EDPC requires Onboard Administrator 2.30 (or later), iLO version 1.70 (or later), and System ROM/BIOS dated 10/1/2008 (or later).

EDPC is not supported on non-ProLiant models, storage blades, PCI blades, and servers that are not properly licensed. These servers are displayed as Unmanageable blades.

NOTE: Power caps set for less than 50% of the difference between maximum power and idle power might become unreachable due to changes in the server. Power caps set for less than 20% are not recommended, and might cause the server to reboot or the server operating system to stop responding.

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