HP StorageWorks 2.12 Edge Switch - Manual (Page 107)

Configuring the Switch
107 Edge Switch Element Manager User Guide
Switch Priority
Setting this value determines the principal switch for the multiswitch fabric. Click
either Principal (highest priority), Default, or Never Principal (lowest priority)
from the Switch Priority drop-down list.
If all switches are set to Principal or Default, the switch with the highest priority
and the lowest WWN becomes the principal switch.
Following are some examples of principal switch selections when switches have
these settings:
■ If you have three switches and set all to Default, the switch with the lowest
WWN becomes the principal switch.
■ If you have three switches and set two to Principal and one to Default, the
switch with the Principal setting that has the lowest WWN becomes the
principal switch.
■ If you have three switches and set two to Default and one to Never Principal,
the switch with the Default setting and the lowest WWN becomes the
principal switch.
Note that at least one switch in a multiswitch fabric needs to be set as Principal or
Default. If all of the switches are set to Never Principal, all of the interswitch
links (ISLs) will segment. If all but one switch is set to Never Principal and the
switch that was Principal goes offline, then all of the other ISLs will segment.
Note: HP recommends configuring switch priority as Default. If you are considering
changing this value to something other than the default, refer to sections on principal
switch selection for multiswitch fabrics in the HP StorageWorks SAN High Availability
Planning Guide for details.
In the audit log you may notice that the Principal setting maps to a number code
of 1, Default maps to a number code of 254, and Never Principal maps to a
number code of 255. The number codes 2-253 are no longer in use.