1. Oracle VM Server for SPARC 3.6 Administration Guide
  2. Using Power Management
  3. Using Power Management
  4. Power Management Features

Power Management Features

The PM features are as follows:

  • CPU core auto-disabling.When the elastic or performance policy is in effect, the Logical Domains Manager automatically disables a CPU core when all the hardware threads (strands) on that core are not bound to a domain. This feature is available only for the SPARC T4 platforms.

  • CPU clock cycle skip.When the elastic policy is in effect, the Logical Domains Manager automatically adjusts the number of clock cycles that execute instructions on the following CPU resources that are bound to domains:

    • Processors (SPARC T4 on domains that run the Oracle Solaris 10 or Oracle Solaris 11 OS)

    • Cores (SPARC M5 only on domains that run the Oracle Solaris 10 OS)

    • Core-pairs (SPARC T5 or SPARC M6 only on domains that run the Oracle Solaris 10 OS)

    • SPARC Cache Cluster (SCC) (SPARC T7, SPARC T8, SPARC M7, SPARC M8, and SPARC S7 series servers only on domains that run the Oracle Solaris 10 OS)

    The Logical Domains Manager also applies cycle skipping if the processor, core, core-pair, or SCC has no bound strands.

  • CPU dynamic voltage and frequency scaling (DVFS).When the elastic policy is in effect, the Logical Domains Manager automatically adjusts the clock frequency of processors or SCCs that are bound to domains running the Oracle Solaris 10 OS. The Logical Domains Manager also reduces the clock frequency on SPARC T5, SPARC M5, and SPARC M6 processors that have no bound strands. On SPARC T7 and SPARC T8 series servers, the clock frequency is reduced on SCCs. This feature is available only on servers starting with the SPARC T5, SPARC M5, and SPARC S7 series server.

  • Coherency link scaling.When the elastic policy is in effect, the Logical Domains Manager causes the hypervisor to automatically adjust the number of coherency links that are in use. This feature is only available on SPARC T5-2 systems.

  • Power limit.You can set a power limit on servers starting with the SPARC T4, SPARC M5, and SPARC S7 series server to restrict the power draw of a system. If the power draw is greater than the power limit, PM uses techniques to reduce power. You can use the ILOM service processor (SP) to set the power limit.

    See the following documents:

    • Oracle Integrated Lights Out Manager (ILOM) 3.0 CLI Procedures Guide

    • Oracle Integrated Lights Out Manager (ILOM) 3.0 Feature Updates and Release Notes

    You can use the ILOM interface to set a power limit, grace period, and violation action. If the power limit is exceeded for more than the grace period, the violation action is performed.

    If the current power draw exceeds the power limit, an attempt is made to reduce the power state of CPUs. If the power draw drops below the power limit, the power state of those resources is permitted to increase. If the system has the elastic policy in effect, an increase in the power state of resources is driven by the utilization level.

  • Solaris Power Aware Dispatcher (PAD). A guest domain that runs the Oracle Solaris 11.1 OS uses the power-aware dispatcher (PAD) on servers starting with the SPARC T5, SPARC M5, and SPARC S7 series server to minimize power consumption from idle or under-utilized resources. PAD, instead of the Logical Domains Manager, adjusts the CPU or SCC clock cycle skip level and DVFS level.

For instructions on configuring the power policy by using the ILOM 3.0 firmware CLI, see “Monitoring Power Consumption” in the Oracle Integrated Lights Out Manager (ILOM) 3.0 CLI Procedures Guide.