24 Installation Guide (AA-RTDWE-TE, November 2005)

Table Of Contents

Edge Switch 2/24 installation guide 47

Fabric parameters

Configure the following parameters, as required by your fabric.

R_A_TOV

Configure resource allocation time-out value (R_A_TOV) in tenth-of-a-second increments. This

variable works with the error detect time-out value (E_D_TOV) variable to control the Edge Switch’s

behavior when an error condition occurs. Resources are allocated to a circuit when errors are

detected and are not released for reuse until the time set by the R_A_TOV value expires. The default

value is 100 tenths (10 seconds). Set a value from 10 tenths through 1200 tenths (1 through 120

seconds).

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 from 2 tenths through 600 tenths (.2 through 60 seconds).

NOTE: Set the same value for E_D_TOV on all Edge 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 Edge Switch for the multiswitch fabric. Select Principal

(highest priority), Default, or Never Principal (lowest priority) from the Switch Priority drop-down list.

Setting these priority values determines the principal Edge Switch selected for the multiswitch fabric.

For example, if you have three Edge Switches in the fabric and set one as Principal, one as Default,

and one as Never Principal, the unit set to Principal becomes the principal Edge Switch in the fabric.

If all Edge Switches are set to Principal or Default, the Edge Switch with the highest priority and the

lowest WWN becomes the principal Edge Switch. Following are some examples of principal Edge

Switch selection when Edge Switches have these settings:

• If you have three Edge Switches and set all to Default, the Edge Switch with the lowest WWN

becomes the principal Edge Switch.

• If you have three Edge Switches and set two to Principal and one to Default, the Edge Switch

with the Principal setting that has the lowest WWN becomes the principal switch.

• If you have three Edge Switches and set two to Default and one to Never Principal, the Edge

Switch with the Default setting and the lowest WWN becomes the principal switch.