Hitachi MK-96RD617-08 User Manual page 140

Note: Throughout this manual, the term prioritized WWN to refers to a
high-priority host bus adapter (for example, wwn01). The term non-
prioritized port refers to a low-priority host bus adapter (for example,
wwn02 and wwn03).
4. Monitor traffic between host bus adapter and ports. You must obtain
statistics about traffic between host bus adapter and ports.
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.
If your network is configured as network B, you must do the following:
– Measure traffic between the port 1A and the three host bus adapters
(wwn01, wwn02 and wwn03.
– Measure traffic between the port 1C and the three host bus adapters
(wwn01, wwn02 and wwn03.
– Measure traffic between the port 2A and the three host bus adapters
(wwn01, wwn02 and wwn03.
– Measure traffic between the port 2C and the three host bus adapters
(wwn01, wwn02 and wwn03.
Figure 6-7 illustrates a graph that describes the I/O rate at the paths
between each port and the host bus adapters. According to the graph, the
I/O rate at the path between 1A and the prioritized WWN (wwn01) was
approximately 400 IO/s at first. The I/O rate at the path between 1A and
the non-prioritized WWNs (wwn02 and wwn03) was approximately 100
IO/s at first. However, as the I/O rate for non-prioritized WWNs (wwn02
and wwn03) gradually increased from 100 IO/s to 200 IO/s, the I/O rate
for the prioritized WWN (wwn01) decreased from 400 IO/s to 200 IO/s.
This indicates that the high-priority production server has degraded. If you
were the network administrator, you probably would like to maintain the
I/O rate for the prioritized WWN (wwn01) at 400 IO/s.
For more information about monitoring traffic, see Setting Priority for Host
Bus Adapters and Analyzing Traffic Statistics.
6-8
Hitachi Universal Storage Platform V/VM Hitachi Performance Manager User's Guide
Server Priority Manager Operation