Viewing i/o rates for disks – HP XP Array Manager Software User Manual
Page 77
In addition, the LDEV tab shows the read hit ratio and the write hit ratio.
•
For a read I/O, when the requested data is already in cache, the operation is classified as a read
hit.
•
For a write I/O, when the requested data is already in cache, the operation is classified as a
write hit.
This section describes how to view the statistics about disk access performance. Before taking the
following steps, you need to start monitoring in accordance with the procedure described in “
and Stopping Storage System Monitoring
” on page 60 and obtain the usage statistics.
Viewing I/O Rates for Disks
Performance Monitor monitors hard disk drives and measures I/O rates (that is, the number of disk
I/Os per second).
To view I/O rates:
1.
Ensure that the Auto LUN window is displayed.
2.
Click the LDEV tab.
The tree displays a list of parity groups and external volume groups.
3.
Select IOPS from the list on the right side of the window.
4.
In the tree, do one of the following:
• To view the I/O rate for each parity group and external volume group, select the Subsystem
folder or a Box folder.
The list on the right displays the I/O rate for each group.
NOTE:
If you select the Subsystem folder, the list displays all parity groups and external volume
groups. To narrow the number of groups to be displayed in the list, select a Box folder. For
example, if you select the Box 1 folder, the list displays only the parity groups whose IDs start
with 1-.
• To view the I/O rate for each volume, select the parity group or external volume group that
contains the volumes.
The list on the right displays the I/O rate for each volume in the selected group.
The displayed statistics are the average and the maximum I/O rates for the period specified in
the From and To boxes.
NOTE:
• 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 “
5.
To display a graph to find out how the I/O rate has been changed, take the following steps;
a.
In the list, select the parity groups, the external volume groups, or the volumes that you want.
XP24000/XP20000 Performance Monitor User Guide
77