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Memory tunables
Table 6-4 shows the memory related tunables. All these tunables are applicable
for the partition and group policies, but only a subset are used for the global
definition.
Table 6-4 Memory related tunables
Tunable Min Default Max Description
Memory notify intervals 1 6 100 The number of contiguous 10 second sample
periods that a memory-related sample must cross a
threshold before PLM will initiate any action.
Memory utilization low 1 50 90 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 1 90 100 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
0 0 2 31 -1 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 ANDed with the result of the
memory utilization high threshold when determining
if additional memory is needed by a partition.
Memory free unused - No - 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 1 1 LMB 256 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.
394 <strong>Advanced</strong> <strong>POWER</strong> <strong>Virtualization</strong> on IBM System p5