IBM SAN32M1, Инструкция по установке и обслуживанию

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133 Chapter 2: Installation tasks
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 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 between 10 tenths and 1200 tenths (1
through 120 seconds).
NOTE: Set the same value for R_A_TOV on all directors and 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 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 switch selected
for the multiswitch fabric. For example, if you have three 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 switch in the
fabric.
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 selection 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.