VARY CORE

Read syntax diagramSkip visual syntax diagram VARY ONlineOFFline CORE nnnn

Authorization

Privilege Class: B

Purpose

Use VARY CORE to add a processor or core to the configuration or remove it from the configuration. The status of multithreading determines whether the VARY CORE command will affect a processor or a core. The term core refers to a physical CPU resource. In a logical partition (LPAR), logical CPUs (processors) are dispatched on cores when multithreading is not installed or not enabled. However, when multithreading is enabled, the core might contain multiple threads, and logical CPUs are dispatched on the threads of the core.

When multithreading is not installed or not enabled, the terms processor and core are synonymous, and the VARY CORE command configures or deconfigures processors. However, when multithreading is enabled, only whole cores can be configured or deconfigured. You cannot configure or deconfigure individual processors. When a core is varied online, the number of threads per core that are supported by the hardware, the z/VM® system, and the current multithreading settings are made available for use. The multithreading settings are set by the MULTITHREADING configuration statement and may be modified by the SET MULTITHREAD command. When a core is varied offline, all of the threads online on that core are stopped and removed.

Operands

ONline
when multithreading is not installed or not enabled, adds a processor to the configuration and makes it available for use by CP. When multithreading is enabled, this operand adds a core to the configuration and makes its processors (threads) available for use by CP.
OFFline
when multithreading is not installed or not enabled, stops the use of a processor and removes it from the configuration. When multithreading is enabled, this operand stops the use of a core and removes its processors (threads) from the configuration.
CORE nnnn
specifies the processor or core to be made available or unavailable. When multithreading is not installed or not enabled, the value nnnn is a hexadecimal number (0000 - 004F) that identifies the address of the processor. When multithreading is enabled, the value nnnn is a 1- to 4-digit hexadecimal number that identifies the core ID.

Usage Notes

  1. Before using the VARY CORE command when multithreading is enabled, it might be useful to issue the QUERY PROCESSORS command to display a list of processors and their associated core IDs. For an example of how the core ID corresponds to a processor address, see QUERY MULTITHREAD.
  2. The last active primary processor or core cannot be varied offline. A primary processor or core is one whose CPU type matches the CPU type of the system's IPL processor.
  3. When multithreading is not installed or not enabled, if the last unparked processor of a secondary processor type is varied offline while all other online processors of that type are parked, CPU affinity will be temporarily suppressed until one of those processors can be unparked.

    When multithreading is enabled, if the last core that contains unparked processors of a secondary processor type is varied offline while all other online processors of that type are parked, CPU affinity will be temporarily suppressed until one of those processors can be unparked.

    A secondary processor is a processor whose CPU type does not match the CPU type of the system's IPL processor.

  4. If the last processor of a secondary processor type is varied offline, CPU affinity will be suppressed for all user IDs and resource pools defined on the system that have CPU affinity on for that secondary processor type. As soon as a secondary processor of that type is varied online, CPU affinity will be unsuppressed. A resource pool that limits a secondary processor type (like IFL) and that has CPU affinity suppressed will apply the resource pool limit against the number of CP CPUs on the system. For example, if the resource pool limit is set to CAPACITY 1.5, then the resource pool is limited to 1.5 CP CPUs when CPU affinity is suppressed. If the resource pool limit is set to LIMITHARD 20%, then the resource pool is limited to 20% of the CP CPU resource when CPU affinity is suppressed and 20% of the IFL CPU resource when CPU affinity is unsuppressed.

Responses

Response 1: 
Command accepted
Core nnnn online Proc pppp[-pppp]
indicates that the specified core and its associated processor or processors are now online and operational.
Response 2:
Command accepted
Core nnnn offline Proc pppp[-pppp]
indicates that the specified core and its associated processor or processors are now offline and not operational.

Messages

  • HCP003E Invalid option - {option|command contains extra option(s) starting with option}
  • HCP026E Operand missing or invalid
  • HCP039E Core ID missing or invalid
  • HCP880E The command processing cannot complete because core nnnn is already online.
  • HCP881E The command processing cannot complete because core nnnn is already offline.
  • HCP882E The VARY command processing cannot complete due to an initialization failure.
  • HCP883E The command processing cannot complete because processor pppp [within core nnnn] is not responsive.
  • HCP884E The command processing cannot complete because core nnnn is the only active primary core.
  • HCP885E The VARY processing cannot complete because the physical vary failed; core nnnn is logically offline.
  • HCP886E The VARY command processing cannot complete because core nnnn is not available.
  • HCP1463I CPU affinity is suppressed for the specified CPU type type
  • HCP1465I CPU affinity is no longer suppressed for the specified CPU type type