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# Computation details for AIX metrics

This topic provides computation information for AIX metrics and indicators. For more information, refer to the following sections:

## AIX Host - CPU Pressure Index

An index between 0 and 100. Higher the value, higher the pressure. This metric is calculated for vSphere hosts and clusters.

The following points about CPI should be noted:

• CPI Value: CPU Pressure Index will have a value in the range of 0 – 100. Higher the number, higher the pressure.
• Minimum value: Minimum value of CPU pressure = CPU Utilization
• Penalty Points: There are Penalty Points for High CPU Queue Length scenarios and they are elaborated in the table that follows.

The following table elaborates computation and other important details for AIX Host - CPU Pressure Index (CPI):

SPI
Calculation
PenaltyThresholdPenaltyComputation
MinMaxCondition

Minimum

Penalty

multiplier

factor

CPU_QUEUE >=
Part 1

AIX Host CPU Queue Length:

AIX Host CPU Queue Length =

Average of CPU Queue Length of partitions
that exceed CPU Queue Length threshold

Configurable

Low: 2
High: 4

5

20

4 x Threshold

4

3 x Threshold

3

2 x Threshold

2

1 x Threshold

1
COUNT >=
Part 2

AIX CPU Queue Exceed Count:

AIX CPU Queue Exceed Count  =
Number of Partitions that exceed threshold

Configurable

Default: 5

520

4 x Threshold

4
3 x Threshold3
2 x Threshold2
1 x Threshold1
Combined CPI

If `CPU_Utilization > CPU_Util_thresh`, then:

`CPU Pressure Index = CPU_Utilization`

Else:

`CPU Pressure Index = CPU Utilization + MAX (Part 1, Part 2)`

## AIX Host - Memory Pressure Index

An index between 0 and 100. Higher the value, higher the pressure.

The following points about MPI should be noted:

• MPI Value: MPI will have a value in the range of 0 – 100. Higher the number, higher the pressure.
• Minimum value: Minimum value of memory pressure = Real Memory Utilization
• Penalty points: There are penalty points for Paging and Virtual Memory Used scenarios, and they are discussed in detail in the table that follows.

The following table elaborates computation and other important details for AIX Host - Memory Pressure Index (MPI):

MPI
Calculation
PenaltyThreshold

Penalty

Computation
MinMaxConditionMinimum
Penalty
multiplier
factor
CPU_QUEUE >=
Part 1Consumed/Active Ratio
(C/A Ratio)
Configurable

Low: 32 MB/sec
High: 64 MB/sec
5

20

4 x Threshold

4

3 x Threshold

3

2 x Threshold

2
1 x Threshold

1

COUNT >=
Part 2BallooningConfigurable

Default: 20

5

20

4 x Threshold

4

3 x Threshold

3
2 x Threshold2
1 x Threshold1
VMU >=
Part 3Over-commitment

Configurable

Low: 70%
High: 80%

1

20

Threshold

VMU -
Threshold
Combined MPI

If `Real_Memory_Utilization > Memory_Util_thresh`:
`Memory Pressure Index = Real_Memory_Utilization`

Else:
`Memory Pressure Index = Memory Utilization + MAX (Part1, Part 2) + Part 3`

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