Fabric Parameters; Bb_Credit; R_A_Tov; E_D_Tov - HP StorageWorks Director 2/140 Installation Manual

4. After you change settings, click Activate.
5. Back up the configuration data when you are finished configuring the switch.
6. Set the director online. For instructions, see "Setting the director online" on page 50.

Fabric parameters

Configure the following parameters as required by your fabric.

BB_Credit

Configure the director to support buffer-to-buffer credit (BB_Credit) from 1 through 60. This is the
value used for all ports, except those configured for extended distance buffering (10-100 km). The
default value is 16. For a description of the buffer-to-buffer credit, refer to the industry specification,
Fibre Channel physical and signaling interface.

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 director'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 between 10 tenths and 1200 tenths (1 through 120
seconds).
NOTE: Set the same value for R_A_TOV on all directors and edge switches in a multi-switch 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).
Set the same value for E_D_TOV on all switches and directors in a multi-switch fabric. If the
NOTE:
value is not the same, the fabric segments.

Switch priority

Setting this value determines the principal director for the multi-switch fabric. Select Principal
(highest priority), Default, or Never Principal (lowest priority) from the Switch Priority list.
Setting these priority values determines the principal director selected for the multi-switch 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.
56 Installing and configuring the director