HP StorageWorks P9000 Performance Advisor Software v5.3 User and Troubleshooting Guide (T1789-96322, August 2011)

The total backend transfers may be compared to the total frontend I/Os and the difference is due to
the effects of the array cache. The total backend transfers load is taken by the RAID groups and
ACP/DKA pairs, where as the total frontend I/O load is taken by the CHIP/CHA ports.
NOTE:
If there are no data points available for the dates selected, blank chart is displayed. If all the data
values are zero for the dates selected, a chart with a horizontal line along the X axis is displayed in
the center of the chart.
IMPORTANT:
For the Hour of the Day report, all the points collected aggregate to the start of the hour. For example,
if data is collected between 1 p.m. and 2 p.m., the aggregate data is displayed at 1 p.m. instead of
2 p.m.
Total I/O Rate Detail report
The Total I/O Rate Detail report displays in a chart format, the number of Sequential I/Os, Random
I/Os, and CFW I/O operations, over the entire period. “Total I/O Rate Detail” on page 414 displays
a sample Total I/O Rate Detail report for the XP1024 Disk Array.
Figure 37 Total I/O Rate Detail
.
The sequential frontend I/Os are when data is read from or written to consecutive addresses. The
random frontend I/Os are when applications address non-consecutive blocks of data. CFWs are a
special class of I/Os generated by HP's P9000 Continuous Access Remote Mirroring software.
NOTE:
If there are no data points available for the dates selected, blank chart is displayed. If all the data
values are zero for the dates selected, a chart with a horizontal line along X axis is displayed in the
center of the chart.
Sample reports414