HP XP RAID Manager Software User Manual
Page 52
Figure 16 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
, you must do the following in this
order:
•
In the WWN tab, select one of the four ports that the HBAs are connected to (i.e., ports
1A, 1C, 2A, and 2C).
•
Set an upper limit to the non-prioritized WWNs (wwn02 and wwn03).
The following figure 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
upper-limit values for non-prioritized WWNs” (page 61)
.
Figure 17 Setting upper limits
6.
Check the result of applying upper limit values. After applying upper limit values, you must
measure traffic at ports. View traffic statistics for the prioritized WWN to check whether the
host performance is improved to a desirable level.
In network B, the desirable I/O rate for the prioritized WWN 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
B, if the upper limit is set to 720 IO/s but the I/O rate for wwn01 is still below 400 IO/s,
the administrator needs to change the upper limit until the I/O rate reaches 400 IO/s.
52
Performance Control operations