Previous Topic: VTAPE_PARM_CACHE_MGMTNext Topic: VTAPE_PARM_FULL_MAXDRVS

Health Checks › VTAPE_PARM_RECALL_SERVER

VTAPE_PARM_RECALL_SERVER

Description

The recommended configuration for the Backstore Engine in a CA Vtape complex is to define one Primary and multiple Failover Servers. The Primary Server processes Externalization and Recall requests on behalf of all CA Vtape subsystems within the same CA Vtape complex. Each Failover Server is configured exactly like the Primary Server, but with its MAXDRIVES set to zero. To trigger failover the SVTn SET MAXDRIVES=nn console command is used to set MAXDRIVES to a nonzero number.

The definition of a Failover Backstore configuration requires that all CA Vtape subsystems within the CA Vtape Complex share the same Group Definitions (VTGROUP), Externalization and Recall related attributes that are defined in the VTPARMS Dynamic Options section. These attributes are:

CacheAutoHoldLowThreshold CacheAutomationSchedule

CacheAutoReleaseHighThreshold CachewarningThreshold

FullMaxdrivesEnforcement* RecallNotificationEvent

RecallServer** RecallServerTimeout

* The attribute FullMaxdrivesEnforcement=Y is required.

** The attribute RecallServer=SERVER is required.

To define a Primary Backstore Server you define the following parameter library attributes:

To define a Failover Backstore Server you define the following parameter library attributes:

In summary, CA Vtape is not configured for Failover Backstore Server operation because the RecallServer attribute does not specify RecallServer=SERVER.

Best Practice

Verify that the current Backstore Engine configuration is defined in accordance with the policies of the intended CA Vtape Complex.

Consider changing the Backstore Engine configuration to the recommended configuration which allows for easy and quick failover with minimal differences in parmlib attribute settings. This makes understanding the configuration and responding to problems simple and straight forward.

Parameters Accepted

None

Debug Support

Yes

Verbose Support

Yes

Reference

For more information, see the chapter "Operational Considerations" in the Configuration Guide.

Messages

SVTH4151E

CA Vtape is not running with the recommended configuration of a Primary Backstore Server and a Failover Backstore Server. The RecallServer attribute in the Dynamic Options section of parmlib is not set to a value of SERVER.