HP XP7 Storage - Manual (Page 50)

Figure 7 Host adapters being monitored
The I/O traffic between the ports and host adapters is now monitored. When the desired amount
of data has been collected, the traffic statistics are reviewed on graphs using the Performance
Monitor window. The following graph shows the measured I/O rate for the paths between each
port and the host adapters. According to the data, the I/O rate for the path between port 1A and
the prioritized WWN (wwn01) was approximately 400 IO/s at first, and the I/O rate for the path
between port 1A and the non-prioritized WWNs (wwn02 and wwn03) was approximately 100
IO/s at first. However, as the I/O rate for the non-prioritized WWNs gradually increased from
100 IO/s to 200 IO/s, the I/O rate for the prioritized WWN decreased from 400 IO/s to 200
IO/s, which indicates a decrease in the performance of the prioritized WWN.
Figure 8 Traffic at ports
To maintain a higher I/O rate (400 IO/s) for the prioritized WWN, you can set upper limits on
the I/O rate for the non-prioritized WWNs to minimize their effect on the performance of the
high-priority production server. When an upper limit is set for the first time, it is recommended that
the upper limit value be approximately 90 percent of the peak traffic level. In Network B, the peak
I/O rate at the paths between each of the four ports and the non-prioritized WWNs (wwn02 and
wwn03) is 200 IO/s, so the recommended upper limit for wwn02 and wwn03 is 720 IO/s (200
Ч 4 Ч 0.90). The following figure shows the result of setting the upper limit of 720 IO/s on the
paths between port 1A and non-prioritized WWNs wwn02 and wwn03 on the WWN tab of the
Performance Control main window.
50 Performance Control operations