HP StorageWorks 2.140 Director Switch User Manual
Page 126

Configuring the Director
124
Director Element Manager User Guide
Note:
Set the same value for E_D_TOV on all directors and directors in a multiswitch
fabric. If the value is not the same, the fabric segments.
Switch Priority
Setting this value determines the principal director for the multiswitch fabric.
Click Principal (highest priority), Default, or Never Principal (lowest priority)
on the Switch Priority drop-down list.
Setting these priority values determines the principal director selected for the
multiswitch fabric. For example, if you have three directors in the fabric and set
one as Principal, one as Default, and one as Never Principal, the unit set to
Principal becomes the principal director in the fabric.
If all directors are set to Principal or Default, the director with the highest
priority and the lowest WWN becomes the principal director. Following are some
examples of principal director selection when directors have these settings:
■
If you have three directors and set all to Default, the director with the lowest
WWN becomes the principal director.
■
If you have three directors and set two to Principal and one to Default, the
director with the Principal setting that has the lowest WWN becomes the
principal director.
■
If you have three directors and set two to Default and one to Never Principal,
the director with the Default setting and the lowest WWN becomes the
principal director.
At least one director in a multiswitch fabric needs to be set as Principal or
Default. If all of the directors are set to Never Principal, all of the interswitch
links (ISLs) will segment. If all but one director is set to Never Principal and the
director that was principal goes offline, then all of the other ISLs will segment.
Note:
We recommend you leave the switch priority setting as Default. If you are
considering setting this value to something other than default, refer to the section on
principal switch selection for multiswitch fabrics in the
HP StorageWorks SAN High
Availability Planning Guide
for details.