Priority Of Switching Destination Paths - Hitachi XP P9500 User Manual

Priority of Switching Destination Paths

Priority of paths varies depending on the architecture of the host machine.
If the architecture of the host is CHRP, the switching destination path is
selected based on four keys. First, the path with the smallest path priority
number (first key) is selected. If there are multiple paths with the smallest
path priority number, the order for selecting a unique path is smallest slot
number (second key), smallest CHA port number (third key), and smallest
PATH_ID value (fourth key).
If the architecture of the host is not CHRP, the switching destination path is
selected based on three keys. First, the path with the smallest path priority
number (first key) is selected. If there are multiple paths with the smallest
path priority number, the order for selecting a unique path is smallest CHA
port number (second key) and then smallest PATH_ID value (third key).
This sub-section explains these keys.
Path priority number
This number indicates the priority level set for each path. Priority levels
can be set from 1 to 255. The lower the number, the higher the priority.
The default is 1. The priority level is set by using OS commands. The
Figure 2-8 Path switching
HDLM Functions
Hitachi Dynamic Link Manager User Guide (for AIX(R))
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