Tunables

Tunables

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The parameters which can be configured in a PLM policy are listed in Table 8-2.
Table 8-2 Tunable parameters

Parameter Description
Memory minimum The minimum memory capacity of the partition. PLM will never leave a partition with less than this amount.
Memory guaranteed The guaranteed amount of memory.
Memory maximum The maximum amount of memory resources PLM will allow a partition to have.
Memory shares A factor used to specify how memory capacity in excess of the memory guaranteed is distributed to partitions in the group. Specifying a value of 0 indicates that a partition will never receive more than the guaranteed memory.
CPU minimum The minimum CPU capacity of the partition. PLM will never leave a partition with less than this amount.
CPU guaranteed The guaranteed amount of CPU whenever a partition's load is greater than the CPU load average low threshold.
CPU maximum The maximum amount of CPU resources PLM will allow a partition to have.
CPU Shares A factor used to specify how CPU capacity in excess of the CPU guaranteed is distributed to partitions in the group. Specifying a value of 0 indicates that a partition will never receive more than the guaranteed CPU.
CPU notify intervals The number of contiguous 10-second sample periods that a CPU-related sample must cross a threshold before PLM will initiate any action.
CPU load average high threshold The processor load average high threshold value. A partition with a load average above this value is considered to need more processor capacity (requestor).
CPU load average low threshold The CPU load average low threshold value. A partition with a load average below this value is considered to have unneeded CPU capacity (donor).
Immediate release of free CPU This indicates whether or not unused excess processor capacity will be removed from the partition and placed in the shared processor pool. A value of no indicates unneeded CPU capacity remains in the partition until another partition has a need for it. A value of yes indicates unneeded CPU capacity is removed from the partition when the partition no longer has a need for it.
Entitled capacity delta (shared partitions only) The percentage increase of CPU entitled capacity to add or remove from a shared processor partition. The value specifies the percent of the partition's current entitled capacity to add or remove.
Minimum entitlement per VP (shared partitions only) The minimum amount of entitled capacity per virtual processor. This attribute prevents a partition from having degraded performance by having too many virtual processors relative to its entitled capacity. When entitled capacity is removed from a partition, virtual processors will also be removed if the amount of entitled capacity for each virtual processor falls below this number.
Maximum entitlement per VP (shared partitions only) The maximum amount of entitled capacity per virtual processor. This attribute controls the amount of available capacity that may be used by an uncapped shared processor partition. When entitled capacity is added to a partition, virtual processors will be added if the amount of the entitled capacity for each virtual processor goes above this number. Increasing the number of virtual processors in an uncapped partition allows the partition to use more of the available processor capacity.
Memory notify intervals The number of contiguous 10-second sample periods that a memory-related sample must cross a threshold of before PLM will initiate any action.
Memory utilization low The memory utilization low threshold below which a partition is considered to have excess memory and will become a memory donor. The units are in percent. The minimum delta between memory_util_low and memory_util_high is 10 percent.
Memory utilization high The memory utilization high threshold at which a partition is considered to need more memory. Units are in percent. The minimum delta between memory_util_low and memory_util_high is 10 percent.
Memory page steal high The page steal rate threshold at which a partition is considered to need more memory. Units are page steals per second. The result of checking this threshold is logically AND'd with the result of the memory utilization high threshold when determining if additional memory is needed by a partition.
Memory free unused Indicates whether or not excess memory capacity will be removed from the partition and placed in the spare memory pool. A value of no indicates unneeded memory capacity remains in the partition until another partition has a need for it. A value of yes indicates unneeded memory capacity is removed from the partition when the partition is no longer using it.
Memory delta The number of megabytes of memory to be removed or added to a partition in any single DR operation. If the value is less than the system's logical memory block (LMB) size, the value is rounded up to the system's LMB size. If the value is greater than the system's LMB size but not a multiple of it, the value is rounded down to the nearest multiple of LMB size.

For more information on configuring Partition Load Management, see PowerVM Virtualization on IBM System p: Introduction and Configuration Fourth Edition, SG24-7940

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Parameter	Description
Memory minimum	The minimum memory capacity of the partition. PLM will never leave a partition with less than this amount.
Memory guaranteed	The guaranteed amount of memory.
Memory maximum	The maximum amount of memory resources PLM will allow a partition to have.
Memory shares	A factor used to specify how memory capacity in excess of the memory guaranteed is distributed to partitions in the group. Specifying a value of 0 indicates that a partition will never receive more than the guaranteed memory.
CPU minimum	The minimum CPU capacity of the partition. PLM will never leave a partition with less than this amount.
CPU guaranteed	The guaranteed amount of CPU whenever a partition's load is greater than the CPU load average low threshold.
CPU maximum	The maximum amount of CPU resources PLM will allow a partition to have.
CPU Shares	A factor used to specify how CPU capacity in excess of the CPU guaranteed is distributed to partitions in the group. Specifying a value of 0 indicates that a partition will never receive more than the guaranteed CPU.
CPU notify intervals	The number of contiguous 10-second sample periods that a CPU-related sample must cross a threshold before PLM will initiate any action.
CPU load average high threshold	The processor load average high threshold value. A partition with a load average above this value is considered to need more processor capacity (requestor).
CPU load average low threshold	The CPU load average low threshold value. A partition with a load average below this value is considered to have unneeded CPU capacity (donor).
Immediate release of free CPU	This indicates whether or not unused excess processor capacity will be removed from the partition and placed in the shared processor pool. A value of no indicates unneeded CPU capacity remains in the partition until another partition has a need for it. A value of yes indicates unneeded CPU capacity is removed from the partition when the partition no longer has a need for it.
Entitled capacity delta (shared partitions only)	The percentage increase of CPU entitled capacity to add or remove from a shared processor partition. The value specifies the percent of the partition's current entitled capacity to add or remove.
Minimum entitlement per VP (shared partitions only)	The minimum amount of entitled capacity per virtual processor. This attribute prevents a partition from having degraded performance by having too many virtual processors relative to its entitled capacity. When entitled capacity is removed from a partition, virtual processors will also be removed if the amount of entitled capacity for each virtual processor falls below this number.
Maximum entitlement per VP (shared partitions only)	The maximum amount of entitled capacity per virtual processor. This attribute controls the amount of available capacity that may be used by an uncapped shared processor partition. When entitled capacity is added to a partition, virtual processors will be added if the amount of the entitled capacity for each virtual processor goes above this number. Increasing the number of virtual processors in an uncapped partition allows the partition to use more of the available processor capacity.
Memory notify intervals	The number of contiguous 10-second sample periods that a memory-related sample must cross a threshold of before PLM will initiate any action.
Memory utilization low	The memory utilization low threshold below which a partition is considered to have excess memory and will become a memory donor. The units are in percent. The minimum delta between memory_util_low and memory_util_high is 10 percent.
Memory utilization high	The memory utilization high threshold at which a partition is considered to need more memory. Units are in percent. The minimum delta between memory_util_low and memory_util_high is 10 percent.
Memory page steal high	The page steal rate threshold at which a partition is considered to need more memory. Units are page steals per second. The result of checking this threshold is logically AND'd with the result of the memory utilization high threshold when determining if additional memory is needed by a partition.
Memory free unused	Indicates whether or not excess memory capacity will be removed from the partition and placed in the spare memory pool. A value of no indicates unneeded memory capacity remains in the partition until another partition has a need for it. A value of yes indicates unneeded memory capacity is removed from the partition when the partition is no longer using it.
Memory delta	The number of megabytes of memory to be removed or added to a partition in any single DR operation. If the value is less than the system's logical memory block (LMB) size, the value is rounded up to the system's LMB size. If the value is greater than the system's LMB size but not a multiple of it, the value is rounded down to the nearest multiple of LMB size.