Analyzing Tape Usage with the Volume Mount Analyzer GFTAVMA Program

GFTAVMA uses the information summarized by GFTAXTR to produce reports about your tape usage. Once you have used GFTAVMA to identify your major tape users, use its other reporting options to help you simulate a tape mount-managed environment. This simulation can help size the DASD buffer and determine the required management classes, data classes, and the filters to identify the tape data sets to be included or excluded from tape mount management.

GFTAVMA determines where each data set belongs in the storage hierarchy, based on a simulation of management class attributes, PRIMARY DAYS and LEVEL 1 DAYS.

You can specify values for these attributes or use the volume mount analyzer's defaults. Each data set has a set of management criteria, based on the usage classification that the volume mount analyzer assigns to the data set. Possible classifications include the following:

DFSMShsm-owned
Temporary
Backup
Single
BCOPY
Active

Data sets that are DFSMShsm-owned are on backup and migration tapes created by DFSMShsm processes.

Data sets classified as temporary have system-generated temporary data set names. These data sets are allocated on the primary or large storage groups, and are deleted by DFSMShsm during space management.

Data sets classified as backup are allocated to the DASD buffer and become eligible for migration the next time that space management is run. They migrate directly to migration level 2.

Data sets classified as single are referenced on only one day during the sample period. These data sets can be directed to migration level 2 after one day.

Data sets classified as BCOPY are data sets that are written and read once during the sample period. Typically, these might be copies of data sets to be taken offsite as part of your disaster recovery procedures. GFTAVMA does not make any assumptions about how these data sets should migrate through the storage hierarchy. They are handled as active data sets.

Any data sets not assigned a usage category are considered as active. They are allocated to the DASD buffer and migrate through the storage hierarchy according to user-specified or volume mount analyzer default values for the volume mount analyzer keywords, LEVEL0DAYS and LEVEL1DAYS. The volume mount analyzer defaults are one day for LEVEL0DAYS and zero days for LEVEL1DAYS.

Related Reading: For more information about analyzing tape usage with the volume mount analyzer, see z/OS DFSMS Using the Volume Mount Analyzer z/OS DFSMS Using the Volume Mount Analyzer.