director 2/64 installation guide

2–50 director 2/64 installation guide
Installing and Configuring the Director 2/64
NOTE: Set the same value for R_A_TOV on all directors and edge switches in a multiswitch
fabric. If the value is not the same on all units, the fabric segments. Also, the value for R_A_TOV
must be greater than the value configured for E_D_TOV.
E_D_TOV
Adjust the E_D_TOV in tenth-of-a-second increments. An error condition occurs
when an expected response is not received within the time limit set by this value. The
default value is 20 tenths (2 seconds). Set a value between 2 tenths through 600 tenths
(.2 through 60 seconds).
NOTE: Set the same value for E_D_TOV on all switches 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. Choose
Principal (highest priority), Default, or Never Principal (lowest priority) from 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.