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HP Hitachi Dynamic Link Manager Software User Manual

Page 45

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2. HDLM Functions

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Figure 2-8: Flow of I/O Data When the Load Balancing Function Is Used

When the load balancing function is used, I/O operations are distributed via multiple

paths (A, B, C, and D). This helps to prevent problems with system performance and

helps prevent bottlenecks from occurring.

2.6.1 Paths to Which Load Balancing Is Applied

This subsection describes, for each type of storage system, the paths to which the load

balancing function is applied.

(1) When Using the Thunder 9500V Series, or Hitachi AMS/WMS Series

When HDLM performs load balancing, it differentiates between load balancing among

owner paths and among non-owner paths. An owner path is a path that passes through

the owner controller for a target LU. When you set up an LU, you have to specify

which CHA to be used as the owner controller for the LU. Because different LUs might