HP XP P9000 for Compatible High Perf FICON Connectivity Software - Manual (Page 49)

3. Set an upper limit to traffic at the non-prioritized port. To prevent decline in I/O rates at
prioritized ports, you set upper limit values to the I/O rate for non-prioritized ports.
When you set an upper limit for the first time, it is recommended that the upper limit be
approximately 90 percent of the 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 for 2A is 180 IO/s.
For details on how to set an upper limit, see “Setting upper-limit values for non-prioritized
WWNs” (page 61) .
4. Check the result of applying upper limit values. After applying upper limit values, you must
measure traffic at ports. You must view traffic statistics for prioritized ports 1A and 1C to check
whether the host performance is improved to a desirable level.
In network A, the desirable I/O rate for ports 1A and 1C is 400 IO/s. If the I/O rate reaches
400 IO/s, production server performance has reached to a desirable level. If production
server performance is not improved to a desirable level, you can change the upper limit to a
smaller value and then apply the new upper limit to the storage system. 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, the
administrator needs to change the upper limit until the I/O rate reaches 400 IO/s.
5. If necessary, apply a threshold. If you want to use threshold control, set threshold values in
the Port tab in the Performance Control main window. You can set threshold values in either
of the following ways:
•
Set one threshold to each prioritized port
In network A, if you set a threshold of 200 IO/s to the port 1A and set a threshold of
100 IO/s to the port 1C, the upper limit on the non-prioritized port (2A) is disabled when
either of the following conditions is satisfied:
The I/O rate for the port 1A is 200 IO/s or lower.
The I/O rate for the port 1C is 100 IO/s or lower.
•
Set only one threshold to the entire storage system
In network A, if you set a threshold of 500 IO/s to the storage system, 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) goes below 500 IO/s.
For details on how to set a threshold, see “Setting a threshold ” (page 56) .
If many-to-many connections link HBAs and ports
The next figure shows an example of a network in which a production server and a development
server are connected to the storage system (Henceforth, this network is referred to as network B).
The host bus adapter (wwn01) in the production server is connected to four ports (1A, 1C, 2A and
2C). The host bus adapters (wwn02 and wwn03) in the development server are also connected
to the four ports.
If many-to-many connections link HBAs and ports 49