HP Power Capping and HP Dynamic Power Capping for ProLiant servers

ManualsBrandsHP ManualsServerHP ProLiant DL360 G5 Server

HP Power Capping and HP Dynamic Power Capping for

ProLiant servers

Technology brief, 2

Edition

Introduction ......................................................................................................................................... 3

Basics of server power control ............................................................................................................... 3

Processor P-states ............................................................................................................................. 4

Clock throttling................................................................................................................................. 4

How power capping functions ............................................................................................................... 5

Maintaining power consumption below the cap ................................................................................... 5

Minimum and maximum power consumption for a server ...................................................................... 5

Differences between HP Dynamic Power Capping and HP Power Capping ................................................. 6

Power provisioning and Dynamic Power Capping ................................................................................ 6

Support for Power Capping in ProLiant servers .................................................................................... 7

Enclosure Dynamic Power Capping ....................................................................................................... 8

Elements of an enclosure power cap ................................................................................................... 8

Operation of Enclosure Dynamic Power Capping ................................................................................. 9

Active power reallocation ............................................................................................................... 10

Enclosure Dynamic Power Capping in mixed blade environments ........................................................ 10

Opting out servers .......................................................................................................................... 10

Setting power caps for servers ............................................................................................................. 10

Setting a power cap for a single server ............................................................................................. 11

Setting a power cap for a group of servers ....................................................................................... 13

Setting a BladeSystem enclosure power cap ...................................................................................... 13

Setting a power cap for a group of enclosures ................................................................................... 14

Using power capping in data center provisioning .................................................................................. 15

Choosing effective power caps ........................................................................................................ 15

Power capping to peak power consumption ...................................................................................... 17

Power capping to average power consumption ................................................................................. 19

Using Enclosure Dynamic Power Capping in power provisioning ............................................................. 19

Power capping for emergency management ...................................................................................... 20

Time-of-day power capping ............................................................................................................. 21

Subtleties of power capping ................................................................................................................ 22

Avoiding power capping conflicts within groups ................................................................................ 22

Powering up groups of servers when using Dynamic Power Capping ................................................... 22

Setting low or unattainable power caps on servers ............................................................................. 22

Peak power reporting and Dynamic Power Capping .......................................................................... 23

Using HP Power Regulator in conjunction with power capping ............................................................ 23

Power capping and CPU utilization .................................................................................................. 23

Power capping and option cards ..................................................................................................... 23

Summary of content (25 pages)

PAGE 1
HP Power Capping and HP Dynamic Power Capping for ProLiant servers Technology brief, 2nd Edition Introduction ......................................................................................................................................... 3 Basics of server power control ............................................................................................................... 3 Processor P-states ................................................................................................
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Providing a guardband for a power capping group ........................................................................... 23 Summary .......................................................................................................................................... 24 For more information .......................................................................................................................... 25 Call to action .........................................................................
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Introduction Server performance-per-watt continues to increase steadily. However, the number of watts-per-server also continues to climb steadily. These increases, combined with the increasing number of servers and density in modern data centers, make planning and managing facility power and cooling resources critically important. HP Power Capping and HP Dynamic Power Capping are ProLiant power management tools that assist the data center administrator in these critical tasks.
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Figure 1. Power use in a typical server Typical Server Power Usage Base Load 13% Hard Drives 4% Processor 33% PCI Slots 15% Fans 7% Memory 28% Processor P-states Processor performance states, or P-states, provide a quick and effective mechanism for adjusting processor power consumption and performance. Both Intel® and AMD® processors support using P-states to decrease processor power consumption by lowering the processor’s core frequency and voltage.
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Figure 2. Power versus performance characteristics for a typical Intel-based ProLiant server with three P-states DL360 G4 Power vs. Work Done Clock Throttling slope P-state slope 400 350 300 Watts Watts 250 P0 P1 200 P2 150 100 50 0 0 500 0.25 1000 1500 0.5 2000 2500 0.75 3000 3500 1.
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produce. However, the enclosure’s power supply array powers HP BladeSystem servers. For a blade server, the maximum available power is the amount of power that the enclosure’s Onboard Administrator reserved for that server blade. Both iLO and Insight Control report this value: iLO reports it as Power supply maximum power for ML and DL servers and as Initial power-on request value for BladeSystem servers.
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trip. HP has tested Dynamic Power Capping to ensure that it can prevent tripping circuit breakers that have a specified trip time of 3 seconds or longer at 50 degrees C and 150 percent overload. Dynamic Power Capping can keep server power consumption below the power cap in real time. Therefore, administrators can use it as an effective tool in planning and managing both electrical provisioning and cooling requirements in the data center.
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Figure 3.
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An administrator can set the enclosure power cap to any value between the lowest total power consumption and the maximum available power for the enclosure.
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Active power reallocation One of the more important features of Enclosure Dynamic Power Capping is the active reallocation of power amongst the server blades over time. After each monitoring cycle, Enclosure Dynamic Power Capping actively reapportions the individual power caps of the server blades based on their individual workloads.
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Setting a power cap for a single server Administrators can set a power cap for an individual server or server blade through iLO or through Insight Control. In the iLO 2 browser-based interface (Figure 5), Power Capping Settings is located beneath the Power Management tab in the Settings subsection. The iLO 2 Power Management Settings screen indicates whether the server supports Dynamic Power Capping. Figure 5.
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In Insight Control, Power Capping is located beneath the HP Power Management Actions section of the interface, as shown in Figure 6. Figure 6.
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Setting a power cap for a group of servers Insight Control is the sole tool for setting power caps for groups of ProLiant ML and DL servers. Using the Insight Control interface (Figure 7), an administrator can apply a group power cap that is between the minimum power and the power supply rating of the entire group. Figure 7.
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Figure 8. Setting an Enclosure Dynamic Power Cap in HP Onboard Administrator 2.60 Setting a power cap for a group of enclosures An administrator can use Insight Control to apply enclosure dynamic power caps to a group of enclosures at the same time. Figure 9 shows five BladeSystem c-Class Enclosures configured as a group in Insight Control. The maximum available power for the group is 31,784 watts. The lower bound of the power cap is 15499 watts.
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the enclosure and to create power caps for the individual server blades. It will then monitor and adjust the individual server blade power caps based on their power demands. Figure 9. Setting a power cap for a group of enclosures in Insight Control Using power capping in data center provisioning Power capping is a tool to help IT organizations manage infrastructure size and costs in the data center.
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indicate that the Total System Input power requirement for this server configuration is 423 watts. This is the predicted maximum amount of power that this server configuration would use under environmental and load conditions. It is one of the numbers that an administrator could use when calculating the maximum power and cooling requirements to support this system in the data center. For a rack containing a group of eight of these servers, the total requirements would be 3384 watts. Figure 10.
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Continuing with this example, Figure 11 shows the Insight Control Group Power Consumption graph for the group of eight servers running a typical variable load application. Insight Control generates this graph using data collected from each server’s power management system. The power management system measures power consumption twice per second and records both the peak and average power consumption.
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which is high in the dynamic range of the servers. So the effects of configuration and environmental changes are ignored. Table 4 shows a summary of the power consumption and capacity savings for the server group. Table 4.
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are not all the same, HP recommends using Insight Control to review the peak power consumption of each server to ensure that the selected Dynamic Power Cap will not significantly limit its actual peak power consumption. Power capping to average power consumption An administrator can further increase provisioning capacity by capping the example group shown in Figure 11 at the average power consumption: 1900 watts.
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Figure 12.
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Time-of-day power capping Insight Control has task-scheduling capabilities. Administrators can create time-of-day power capping for a server or group of servers that lowers and raises power levels in a pre-determined pattern, typically on a daily cycle. Lowering the power cap on a group of servers when electricity rates are highest will lower operating costs. It decreases the average power use by the servers and, indirectly, decreases required cooling.
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Subtleties of power capping Avoiding power capping conflicts within groups Insight Control is a powerful tool for setting and managing power caps across defined groups of servers, including SIM collections. It is important to remember, however, that except for Enclosure Dynamic Power Capping, power caps are ultimately set at the individual server level. Insight Control apportions a group power cap as individual power caps to all of the servers in the group. Power capping is also completely non-hierarchical.
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Peak power reporting and Dynamic Power Capping Both iLO and Insight Control report the power metrics for ProLiant servers, including peak power consumption. The power monitoring system for servers records peak power consumption as the largest half-second power measurement in a 5-minute period. It can take up to one-half second to bring a server’s power consumption back below the cap. As a result, it is possible to see reported peak power numbers that are several watts above a server’s power cap value.
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Administrators should consider the following factors for determining the amount of power to reserve as a guardband: • • • The guardband should allow any individual server in the group to power up at full power while constraining other servers on the same circuit to their cap value. The preceding “Powering up groups of servers when using Dynamic Power Capping” section illustrates this.
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For more information Source Hyperlink HP Power Management http://www.hp.com/go/powercapping HP Insight Control http://www.hp.com/go/insightcontrol HP Integrated Lights-Out http://www.hp.com/go/ilo HP SIM page on hp.com http://www.hp.com/go/hpsim Dynamic Power Capping TCO and Best Practices white paper http://h71028.www7.hp.com/ERC/downloads/4AA2-3107ENW.pdf Dynamic Power Capping support matrix http://h18004.www1.hp.com/products/servers/management/dynamic-powercapping/support.