Hitachi MK-96RD617-08 - Manual (Page 104)

5-22 Performance Monitor Operations
Hitachi Universal Storage Platform V/VM Hitachi Performance Manager User’s Guide
The list displays the following items:
• : When the green checkmark icon is displayed on the left of a DRR,
the graph illustrates changes in usage rate for the DRR.
• ID: This column displays ID numbers for DRRs.
• Usage:
– The Ave. (Total) column displays the average usage rate in the
specified period.
– The Max. column displays the maximum usage rate in the specified
period.
Viewing Write Pending and Cache Memory Usage Statistics
Performance Monitor lets you view write pending rates. A write pending rate
indicates the ratio of write-pending data to the cache memory capacity.
Performance Monitor displays the average and the maximum write pending
rate in a specified period. When you select shortrange for storing period of
statistics, Performance Monitor also displays the average and the maximum
usage statistics about the cache memory in a specified period. In addition,
Performance Monitor can display a graph illustrating changes in write pending
rate or usage statistics of the cache memory within that period.
To view the write pending rate or usage statistics of the cache memory:
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 details on the types of storing period of statistics, see Understanding
Statistical Storage Ranges.
The items displayed in the list are a little different depending on the
selection of the storing period: longrange or shortrange. The write
pending rates are displayed by both selection, but usage statistics of the
cache memory are displayed only when you select shortrange.
4. In the tree, select the Cache folder.
The list on the right displays the write pending rates. If you select
shortrange for the storing period of statistics, the list also displays usage
statistics about the cache memory.
Average and maximum usage rates for the period specified in From and To
are displayed.
If you change the date and time in From and To and then click Apply,
Performance Monitor recalculates the write pending rates and usage
statistics about the cache memory, and updates information in the list. To
change the date and time in From and To, use the arrow buttons and the
sliders (for details, see Performance Management Window, Physical Tab).