Tape Management Systems › Tape Management System Interface › Virtual Volume Expiration Date and Automatic Subgroup Adjustment

Virtual Volume Expiration Date and Automatic Subgroup Adjustment

Each CA Vtape Externalization Group defined in the Group Definitions is automatically broken down into three subgroups, Short, Medium, and Long. Virtual Volumes are assigned to a subgroup based on the settings of the ShortRetention, MediumRetention, CatalogManagedSubgroup, NeverExpireSubgroup, and SpecialRetentionSubgroup attributes. The purpose of these subgroups is to break the Virtual Volumes in an Externalization Group up into subsets with common retention periods so that a Backstore Tape can expire without needing to be Recycled.

By default subgroup assignment is controlled by the expiration date or retention period coded in the JCL or dynamic allocation which first mounted the Virtual Volume. While this approach works well for most sites, it does not take into consideration that Tape Management Systems often have retention rules that override the retention coded in JCL. It also does not take into consideration that occasionally tapes have their expiration dates manually extended or shortened.

Activating the interface allows CA Vtape to retrieve the Virtual Volume expiration date from the Tape Management System when Externalizing and Recycling Virtual Volumes and automatically adjust the subgroup assigned. Automatic subgroup adjustment allows CA Vtape to more accurately group data on Backstore Tapes to eliminate the need to Recycle that same data in the future. It also allows any changes to the retention attributes in the parmlib Group Definitions, changes to the Tape Management System rules or manual updates to expiration dates to be automatically applied. This allows the stacking process to change dynamically as your storage management requirements change.