Automated Tape Libraries and Virtual Tape Support › CA Vtape

CA Vtape

CA Vtape uses your existing tape and DASD hardware to implement virtual tape with mainframe-class reliability and performance.

The CA Vtape interface to CA TLMS is internal and does not require user exits to implement. A CA Vtape parameter that is defined in the VTPARMS member of PARMLIB activates this internal interface. When the TapeManagementSystem parameter is set to TLMS or AUTO and CA TLMS is discovered on the system, CA Vtape activates the internal interface to provide the following benefits:

• The retention schedule for the virtual volumes comes from CA TLMS for use in backstore processing to group together virtual volumes with similar expiration attributes.
• During the externalization processing the container field (ACTVOL) in the virtual volume is updated in the VMF to reflect the physical volume it is written to.

In most cases, CA Vtape virtual volumes are handled as if they are real volumes. CA TLMS remains in control of scratch processing, which must be coordinated with CA Vtape. CA Vtape provides a job in CAI.INSTALL(TLMS) to perform scratch synchronization. Schedule this job to run after the daily TLMSTRS run.

The interface between CA Vtape and CA TLMS is documented in the CA Vtape User Guide. Complete planning and implementation steps are provided, but some of the main points include:

• Define an exclusive range of virtual volumes in the VMF for CA Vtape use.
• CA Vtape writes virtual volumes to the physical container volume during externalization processing as secondary files. CA TLMS writes the Multi-Data Set records (MDS) to contain information about secondary files. Ensure that you have extended the VMF to define enough MDS records to contain all the secondary file information that describes the virtual volumes.
• The MDS records are freed when all virtual volumes on the physical tape are expired.
• You can run the CA Vtape RECYCLE utility to recover fragmented physical tape space by copying active virtual volumes to new backstore tapes. This process also frees up MDS records.
• CA TLMS can report on the physical volumes that are externalized and the virtual volume to physical volume mapping. You can execute CA TLMS CAI.CTAPEARL member TLERPT23 to create this report. This information is important in disaster recovery planning.