5-8 Performance Monitor Operations
Hitachi Universal Storage Platform V/VM Hitachi Performance Manager User’s Guide
Monitoring Resources in the Storage System
This section describes how to view usage statistics about resources in the
storage system.
Before taking the following steps, you need to start monitoring in accordance
with the procedure described in Monitoring Options Window and obtain the
usage statistics.

Viewing Usage Statistics on Parity Groups

Performance Monitor monitors parity groups and lets you view the average
and the maximum usage rate in a specified period. Performance Monitor also
displays a graph illustrating changes in parity group usage within that period.
To view usage statistics about parity groups:
1. Ensure that the Performance Management window is displayed.
2. In the tree, click the Physical tab.
3. In the list above the tree, select the storing period of statistics from
longrange and shortrange for display.
For information on storing period of statistics, see Understanding Statistical
Storage Ranges.
When you view usage statistics about parity groups, the items displayed in
the list by selecting longrange and shortrange are the same.
4. In the tree, select the Parity Group folder.
The list on the right displays usage statistics about parity groups. The
displayed statistics are the average and the maximum usage rates for the
period specified in the From and To boxes.
The list displays up to a maximum of 4,096 resources at a time. If the
number of resources exceeds 4,096, use Previous and Next to display the
remaining resources.
– If you change the date and time in the From and To boxes and then
click Apply, Performance Monitor recalculates usage rates and updates
information in the list. To change the date and time in From and To
boxes, use the arrow buttons and the sliders (for details, see
Performance Management Window, Physical Tab).
– If an exclamation mark (!) is displayed before a usage rate, the
reported parity group usage rate is likely to be inaccurate, because the
configuration has changed (e.g., volumes have been moved by Volume
Migration or ShadowImage, or formatted by Virtual LVI or Open Volume
Management). For information on using Volume Migration, contact the
Hitachi Data Systems Support Center (see Calling the Hitachi Data
Systems Support Centeri.
– If a plus mark (+) is displayed before a usage rate 0, such as "+0", the
usage rate is not completely 0 but less than 1.