HP XP P9000 Performance Advisor Software - Manual (Page 369)

Viewing variations in the LDEV response time
You can identify the LDEVs that are experiencing response time variations by analyzing their read
and write response time values.
Consider a scenario where your application is associated with multiple LDEVs and experiencing a
slow response time. As some of the components, such as RAID groups are shared, their utilization
might not indicate an impact on the application. Instead, verify whether there are variations in the
response time of the LDEVs associated with your application. Further, verify the utilization of components
associated with those LDEVs, such as the RAID group, CHA MP (applicable only for the XP disk arrays),
and the MP blades (applicable only for the P9000 disk arrays) to take the appropriate action.
P9000 Performance Advisor analyses the previous average read and write response values of an
LDEV for the duration that you specify in the User Settings screen (see “
Setting the duration to predict
the LDEV response time ” on page 96). It computes a reference value based on the actual data for the
specified duration and verifies whether the average read and write response values of an LDEV are
within or beyond the reference value. If the values are high, it displays a
for the corresponding
LDEV in the LDEV table. You can also click the to view a graphical representation of the average
read and write response time values in the Chart Work Area. The graph displays the variations in
the average read and write response time of the selected LDEV.
NOTE:
•
The reference value used by P9000 Performance Advisor cannot be configured.
•
The corresponds to the average read and write response time variations for an
LDEV.
P9000 Performance Advisor also displays the duration when the variations were observed. The
durations and the corresponding dates when the load was high on the LDEVs are displayed in a table.
If you do not want to view the table, clear the Show Peak Load check box in the Chart Work Area.
You can also view the performance graphs related to other metrics to analyze the cause for the
performance load on the LDEVs. The following image shows the variations in the LDEV response time
for 53040, which belongs to the P9500 Disk Array type.
HP StorageWorks P9000 Performance Advisor Software User Guide 369