HP Hitachi Dynamic Link Manager Software - Manual (Page 56)

What is the Dynamic Load Balance Control Function
In a system configuration in which multiple hosts and a storage system are
connected, the I/O processing load tends to concentrate on the controller of
the storage system, causing throughput performance of the entire system
decrease. The dynamic load balance controller function evaluates such load
statuses on the controller and prevents storage system performance from
decreasing.
The following is a list of the storage systems that provide the dynamic load
balance controller function and are supported by HDLM.
• Hitachi AMS2000 series #
• Hitachi SMS series #
• HUS100 series
#
For using the dynamic load balance controller function there are
restrictions on the versions of the microprograms you install. For details,
see the release notes of HDLM.
Dynamic I/O Path Control Function
In a storage system in which the dynamic load balance controller function is
installed, enable the dynamic I/O path control function to make the HDLM
load balancing effective.
When the dynamic I/O path control function is enabled, the controller
selected by the dynamic load balance controller function is recognized as the
owner controller. Other controllers are recognized as non-owner controllers.
The dynamic I/O path control function can be enabled or disabled based on
each host, connected storage system, or LU.
The dynamic I/O path control function can be specified by using the HDLM
command's set operation. For details about the set operation, see set (Sets
Up the Operating Environment) on page 6-15 .
Error Management
HDLM collects information for troubleshooting into log files. HDLM can also
filter error information according to the error level when collecting the
information. The following figure shows the flow of data when error
information is collected on a host which is running HDLM .
2-32
HDLM Functions
Hitachi Dynamic Link Manager User Guide for Linux ®