HP StorageWorks XP24000/XP20000 Performance Control User Guide (T5214-96087, September 2010)

4. Monitor traffic between host bus adapter and ports. You must obtain statistics about traffic between
HBA and ports.
If your network is configured as network B, you must do the following:
• Measure traffic between port 1A and the three HBAs (wwn01, wwn02 and wwn03).
• Measure traffic between port 1C and the three HBAs.
• Measure traffic between port 2A and the three HBAs.
• Measure traffic between port 2C and the three HBAs.
Figure 11 illustrates the I/O rate using the paths between each port and the HBAs. According
to the graph, the I/O rate using the path between 1A and the prioritized WWN (wwn01) was
approximately 400 IO/s at first. The I/O rate using the path between 1A and the non-prioritized
WWNs (wwn02 and wwn03) was approximately 100 IO/s at first. However, as the I/O rate
for non-prioritized WWNs (wwn02 and wwn03) gradually increased from 100 IO/s to 200
IO/s, the I/O rate for the prioritized WWN (wwn01) decreased from 400 IO/s to 200 IO/s.
This indicates that the high-priority production server has degraded.
For more information about monitoring traffic, see “Setting Priority for HBAs” on page 40 and
“Analyzing Traffic Statistics in the WWN Tab” on page 39.
Figure 11 Traffic at ports
.
5. Set an upper-limit to traffic between ports and the non-prioritized WWN to prevent decline in
I/O rates at prioritized WWNs.
When you set an upper-limit for the first time, the upper-limit should be approximately 90 percent
of the peak traffic level.
In network B, the peak I/O rate using the paths between port 1A and the non-prioritized WWNs
(wwn02 and wwn03) is 200 IO/s. The peak I/O rate using the paths between port 1C and the
non-prioritized WWNs is also 200 IO/s. The peak I/O rate using the paths between port 2A
and the non-prioritized WWNs is also 200 IO/s. The peak I/O rate using the paths between
port 2C and the non-prioritized WWNs is also 200 IO/s. So, the recommended upper-limit for
the non-prioritized WWNs is 720 IO/s (= 200 × 4 × 0.90).
If your network is configured as in Figure 8, you must do the following in this order (see Figure
12):
a. In the WWN tab, select one of the four ports that the HBAs are connected to (that is, ports
1A, 1C, 2A, or 2C).
b. Set an upper-limit to the non-prioritized WWNs (wwn02 and wwn03).
Figure 12 is the result of setting the upper-limit of 720 IO/s using the paths between 1A and the
non-prioritized WWNs. For details on how to set an upper-limit, see “Setting Upper-Limit Values
to Traffic at Non-prioritized Ports” on page 34.
XP Performance Control Operations30