Setting up the System, Tape Management, and Third-Party Products › Oracle Host Software Component (HSC) and Storage Management Component (SMC) › Method Four: Use DFSMS or CA Allocate to Perform Unit Replacement

Method Four: Use DFSMS or CA Allocate to Perform Unit Replacement

You can avoid the HSC exits and HSC TAPEREQ parameters by using DFSMS and CA Allocate to do unit replacement.

A separate unit esoteric is coded for the CA Vtape Virtual Devices and added to the NNLBDRV HSC parameter as documented in the section Method Three: HSC/SMC Parameters. A new data class is defined in SMS and the SMS data class ACS routine or the CA Allocate ASR is updated to assign that data class to data sets that should be intercepted by CA Vtape. The CA Allocate ASR is updated to assign an esoteric containing only the CA Vtape Virtual Devices to the mount request. The new data class is added to the CA Vtape Data Class Filter List.

When a scratch mount is requested, DFSMS or CA Allocate directs it to CA Vtape by assigning the data class and then assigning the CA Vtape esoteric. HSC/SMC ignores the mount because the esoteric does not contain any HSC/SMC controlled devices.

The Virtual Devices still need to be added to the unit esoterics normally used by the applications so that read requests can be properly processed by CA Vtape. Because read requests are for existing data sets, not new data sets, DFSMS, or CA Allocate is not invoked and cannot do unit replacement.