HP Hitachi Dynamic Link Manager Software User Manual

Page 40

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2. HDLM Functions

Figure 2-7: Overview of load balancing

(2) When Using the Lightning 9900V Series, Hitachi USP, Universal Storage

Platform V/VM, Virtual Storage Platform, Hitachi AMS2000 Series, or Hitachi SMS

All online paths are owner paths. Therefore, for the example in Figure 2-6: Flow of

I/O Data When the Load Balancing Function Is Used, the load is balanced among the

four paths A, B, C, and D. If one of the paths were to become unusable, the load would

be balanced among the three, remaining paths.

2.6.2 Load Balancing Algorithms

HDLM has the following six load balancing algorithms:

• The Round Robin algorithm
• The Extended Round Robin algorithm
• The Least I/Os algorithm
• The Extended Least I/Os algorithm
• The Least Blocks algorithm