HP StorageWorks XP24000/XP20000 Performance Control User's Guide (T5214-96047, December 2008)

Figure 5 Network A (One-to-one connections between HBAs and ports)
If one-to-one connections are established between HBAs and ports, take the following major steps:
1. Set priority to ports on the storage system using the Port tab of the Performance Control window.
In network A, the ports 1A and 1C are connected to high-priority production servers. The port
2A is connected to a low-priority development server. Therefore, the ports 1A and 1C should be
given high priority, and the port 2A should be given low-priority.
Figure 6 on page 28 shows a portion of the Performance Control window in which the abbrevi-
ationPrio. indicates that the associated port is given high priority, and the abbreviation Non-Prio.
indicates that the port is given low-priority.
NOTE:
Throughout this manual, the term prioritized port is used to refer to a high-priority port. The term
non-prioritized port is used to refer to a low-priority port.
Figure 6 Priority specified in the Performance Control window
2. Monitor traffic at ports. You must obtain statistics about traffic at each port on the storage system.
Figure 7 is a graph that illustrates 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.
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