6-4 Server Priority Manager Operation
Hitachi Universal Storage Platform V/VM Hitachi Performance Manager User’s Guide
Prio. indicates a prioritized port.
Non-Prio. indicates a non-prioritized port.
2. Monitor traffic at ports. You must obtain statistics about traffic at each port
on the storage system.
There are two types of traffic statistics: the I/O rate and the transfer rate.
The I/O rate is the number of I/Os per second. The transfer rate is the size
of data transferred between a host and the storage system. When you view
traffic statistics in the window, you select either the I/O rate or the transfer
rate. The Port-LUN tab of the Performance Management window lets
you view a line graph illustrating changes in traffic.
Figure 6-3 is a graph illustrating changes in the I/O rate for the three ports
(1A, 1C, and 2A). According to the graph, the I/O rate for 1A and 1C was
approximately 400 IO/s at first. The I/O rate for 2A was approximately 100
IO/s at first. However, as the I/O rate for 2A gradually increased from 100
IO/s to 200 IO/s, the I/O rate for 1A and 1C decreased from 400 IO/s to
200 IO/s. This fact indicates that the high-priority production servers have
suffered lowered performance. If you were the network administrator, you
probably would like to maintain the I/O rate for prioritized ports (1A and
1C) at 400 IO/s. To maintain the I/O rate at 400 IO/s, you must set an
upper limit to the I/O rate for the port 2A.
For detailed information about monitoring traffic, see Setting Priority for
Ports on the Storage System and Analyzing Traffic Statistics.
400
I/O rate （IO/s）
200
time
100
300 prioritized ports
（1A and1C）
non-prioritized port
（2A）