Collecting data – HP XP Performance Advisor Software User Manual

Page 112

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Metric Category

Metric

Description

Cache Usage Util

Cache Writes Pending Util

Cache Sidefile Usage Util

Cache Usage Utilization, Cache

Writes Pending Utilization, Cache

Sidefile Usage Utilization

THP Pool Occupancy

The usage rate of a XP Thin

Provisioning (THP) pool.

The THP Pool Occupancy is

displayed only for XP24000.

SNAPSHOT Pool Occupancy

The usage rate of a Snapshot pool.

The Snapshot Pool Occupancy is

displayed only for XP 24000.

Utilization Metrics, cont.

Journal File Usage Util

The usage rate of a Continuous

Access Journal File.

Backend Metrics

LDEV Sequential Read Tracks

LDEV Non-sequential Read Tracks

LDEV Write Tracks

RAID Group Se-

quential Read Tracks

RAID Group Non-se-

quential Read Tracks

RAID Group Write Tracks

ACP Pair Sequential Read Tracks

ACP Pair Non-se-

quential Read Tracks

ACP Pair Write Tracks

Response Time Metrics

Average Read Response

Maximum Read Response

Average Write Response

Maximum Write Response

Single LDEVs

Collecting data

Use PA XP to display data collected at different collection rates in the same chart as if all of the data were

collected at the same collection rate. (This occurs when collecting from multiple DKCs at different rates.)
To manage varying collection rates, PA XP uses cubic spline interpolation or approximation. The basis

for the interpolation depends on the master that is selected. The master will be the set of data points

that represent the most recent collection period, as well as the shortest collection period. (The shortest

collection period is defined as the collection period where the data is most frequently collected.) After the

system determines the master, the other data points are interpolated to match the master. For example, if

you collected a set of data at five-minute intervals on one DKC, and another set of data at one-minute

intervals on another DKC, the system will carry out its cubic spline interpolation (approximation)

based on the data collected at one-minute intervals. All data will display as if it were being collected

at one-minute intervals.
If the data has the same number of collection points, the master will be the data collected from the DKC

with the shortest collection period. The system will never return more than 1,000 points. (10 points of

data are set as the default.)

NOTE:

If a chart is not produced after you click Show Chart, the time lines of the selected metrics might not

align. In other words, it is possible that old data values (for example, values from one week ago) are not

aligning with new data values (for example, values from yesterday). Other possible causes are that no

data was collected for the time specified, or that data was not collected from the DKC. Check the Java

Console for messages. Click View, and then click Java Console in your browser.

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Charts

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