Server Priority Manager Operati on 6-9
Hitachi Universal Storage Platform V/VM Hitachi Performance Manager User’s Guide
400
I/O rate （IO/s ）
200
time
100
300 prioritized WWN
（wwn01）
non-prioritized WWN
（wwn02 and wwn03）
Figure 6-7 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 at the paths between port 1A and the non-
prioritized WWNs (wwn02 and wwn03) is 200 IO/s. The peak I/O rate at
the paths between port 1C and the non-prioritized WWNs is also 200 IO/s.
The peak I/O rate at the paths between port 2A and the non-prioritized
WWNs is also 200 IO/s. The peak I/O rate at 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 6-4, you must do the following in
this order:
a. In the WWN tab, select one of the four ports that the HBAs are
connected to (i.e. ports 1A, 1C, 2A, and 2C).
b. Set an upper limit to the non-prioritized WWNs (wwn02 and wwn03).
Figure 6-8 is the result of setting the upper limit of 720 IO/s to the paths
between 1A and the non-prioritized WWNs. For details on how to set an
upper limit, see Setting Priority for Ports on the Storage System.
Figure 6-8 Setting Upper Limits