HP StorageWorks XP Remote Web Console Software - Manual (Page 9)

XP Performance Control user guide 9
administrator, you might want to maintain the I/O rate for prioritized ports 1A and 1C at 400 IO/s.
To do this, set an upper limit to the I/O rate for port 2A.
For detailed information about monitoring traffic, see ”
Setting the priority of ports on arrays ” on
page 18 and ” Measuring traffic between host bus adapters and ports for many-to-many connections ”
on page 19.
Figure 3 Traffic at ports on network A
3. Set an upper limit to traffic at non-prioritized ports. To maintain I/O rates at prioritized ports, set
upper limit values to the I/O rate for non-prioritized ports.
When you first set an upper limit, HP recommends an upper limit of approximately 90 percent of peak
traffic. In network A, the peak I/O rate for the non-prioritized port (2A) is 200 IO/s, so the
recommended upper limit is 180 IO/s.
For detailed information, see ”
Setting upper limit values for traffic at non-prioritized ports or WWNs ”
on page 20.
4. Check the result of applying upper limit values. After applying upper limit values, measure traffic at
ports by viewing traffic statistics for prioritized ports 1A and 1C to check whether the host
performance has improved to a desirable level.
In network A, if the desirable I/O rate (400 IO/s for ports 1A and 1C) has not been achieved,
change the upper limit for port 2A to a lower value and apply the new upper limit to the array. In
network A, if the upper limit is set to 180 IO/s but the I/O rate for 1A and 1C is still below 400 IO/s,
reduce the upper limit until the I/O rate reaches 400 IO/s.
5. If necessary, apply a threshold. To use threshold control, set threshold values in the Port tab in the XP
Performance Control pane. You can set threshold values in either of the following ways:
• Set one threshold for each prioritized port.
In network A, if you set a threshold of 200 IO/s for port 1A and 100 IO/s for port 1C, the upper
limit on the non-prioritized port (2A) is disabled when either of the following conditions is met:
• I/O rate for port 1A is 200 IO/s or lower
• I/O rate for port 1C is 100 IO/s or lower
• Set only one threshold for the entire array.
In network A, if you set a threshold of 500 IO/s for the array, the upper limit on the non-prioritized
port (2A) is disabled when the sum of the I/O rates for all prioritized ports (1A and 1C) falls below
500 IO/s.
For detailed information, see ” Setting thresholds ” on page 21.
Procedure for many-to-many connections between HBAs and ports
Figure 4 shows an example of a network where a production server and development server are
connected to the array. (Henceforth, this network is referred to as network B.) The host bus adapter