Universal Storage Platform V/Vm, Virtual Storage Platform, Hitachi Ams2000; Series, Or Hitachi Sms; Load Balancing Algorithms - Hitachi XP P9500 User Manual

remaining usable owner paths. When all owner paths cannot be used, load
balancing is performed among the non-owner paths.
For the example in
suppose that in the owner controller of LU0 is CHA0. When the LU is
accessed, the load is balanced between the two physical paths A and B, which
are both owner paths. When one of the paths (A) cannot be used, then the
LU is accessed from the only other owner physical path (B). When both of the
owner physical paths (A and B) cannot be used, the load is then balanced
between two other, non-owner physical paths (C and D).
When Using the Lightning 9900 Series, 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
Flow of I/O Data When the Load Balancing Function Is Used on page
the load is balanced among the four physical paths A, B, C, and D. If one of
the physical paths were to become unusable, the load would be balanced
among the three, remaining physical paths.

Load Balancing Algorithms

HDLM has the following six load balancing algorithms:
• The Round Robin algorithm
• The Extended Round Robin algorithm
Figure 2-7 Overview of Load Balancing on page
Figure 2-7 Overview of Load Balancing
HDLM Functions
Hitachi Dynamic Link Manager User Guide (for Solaris(R))
2-13,
Figure 2-6
2-12,
2-13