HP XP P9000 Performance Advisor v6.0 Software Troubleshooting and FAQs Guide

NA is displayed for the LDEVs that belong to the continuous access journal pools when you want
to view the performance values for the following metrics:
• MAX Write Resp
• AVG Write Resp
• Random Write Cache Hits
• Random Writes Sequential Write Cache Hits
• Sequential Writes
• Random MB Writes
• Sequential MB Writes
The above mentioned metrics are not supported in HP XP P9000 Performance Advisor for the
continuous access journal pool LDEVs.
In charts, the following metrics are disabled for the LDEVs that belong to the continuous access
journal pools:
• FrontEnd IO metrics: LDEV Random Writes and LDEV Sequential Writes
• FrontEnd MB metrics: Random MB Write and Sequential MB Write
• Response Time metrics: Maximum Write Response and Average Write Response
Predict variations in LDEVs response time
NOTE: Viewing variations in LDEVs response time is a new feature introduced in HP XP P9000
Performance Advisor from v4.6 onwards. Therefore, these FAQs are not applicable to HP XP
P9000 Performance Advisor versions prior to v4.5.
Can I set the duration for HP XP P9000 Performance Advisor to predict the average read and write
response time of LDEVs?
Yes. You can set the duration that HP XP P9000 Performance Advisor must use to predict the
average read and write response time of LDEVs.
Complete the following steps to select the duration:
1. Click Settings in the left pane.
2. Select User Settings.
The User Settings screen appears.
3. In the Data Analysis Settings section, select the duration from the drop-down list. You can
select a maximum of 7 days. By default, HP XP P9000 Performance Advisor considers a
duration of 2 days for the prediction.
4. Click Save.
What is the minimum and maximum duration that can be set?
You can select a maximum of 7 days. By default, HP XP P9000 Performance Advisor considers a
minimum duration of 2 days for the prediction.
Can you provide a use case on why it is necessary to predict variations in LDEVs response time?
Consider that your application has association with multiple LDEVs and is experiencing slow
response time. Because some of the resources, such as RAID group and CHIP MP are shared, their
utilization might not indicate an impact on the application in question. Instead, you can identify
the LDEV that is experiencing variations in its response time by analyzing the LDEV's read and
write response time values. Then, you can verify the utilization of associated resources, such as
CHIP MP, RAID group, and DKA to take the appropriate action. You can view performance graphs
related to other metrics and analyze the cause for the performance load on the LDEVs.
When is the displayed for an LDEV on the Troubleshooting screen?
72 Frequently Asked Questions