1. OVERVIEW › 1.2 VTS Component › 1.2.1 Capabilities

1.2.1 Capabilities

The VTS component provides data integration and reporting
capabilities that aid in the analysis and reporting of
virtual tape subsystems in the following areas:

o  Virtual Tape Cache Management

   Virtual storage subsystems use a DASD cache (buffer) as a
   high speed staging area where virtual tape volumes are
   created and accessed.  Monitoring DASD cache performance
   is necessary to fine tune subsystem parameters and virtual
   tape policies to ensure optimal performance.  The VTS
   component files provide comprehensive cache performance
   statistics that can be used to validate whether parameters
   and policies maximize cache performance.

o  Virtual Tape Volume Management

   The VTS component files provide information to determine
   the suitability of virtual tape as a storage medium.
   Excessively large data sets may not be appropriate because
   they can dominate the limited DASD cache.  With the VTS
   component files, a profile of virtual tape volumes,
   retrieval patterns, and longevity can be established and
   monitored.

o  Virtual Tape Performance Analysis

   The VTS component database files contain key measurements
   that support day to day performance and throughput
   analysis, and bottleneck detection.

   The ability of the physical tape drives and cartridges to
   keep pace with virtual tape access is affected by a number
   of factors, all of which can be measured and reported on
   using the VTS component database files.


o  Capacity Planning

   The higher timespan VTS component database files support
   trending and forecasting of critical measurements such as
   mount times, virtual volume size, real tape cartridge
   usage, and tape drive contention.  Monitoring these trends
   provides a means to take action before performance levels
   deteriorate.

o  Management Reporting and Policy Creation

   Information in the VTS component database files can be
   grouped and summarized to create useful virtual tape
   subsystem management-level reports.  Reports or one-page
   management summaries that compare actual performance
   against proposed service level objectives allow the
   creation of policies that are rational and achievable.
   Once policies are established, reports can be created to
   track actual performance against objectives.