CA Dynam for VSE User Guide

Using CA Dynam/T
• CA Dynam/T checks that the logical unit being opened has been assigned
to a tape drive to prevent abnormal termination with the IBM message
4883I INVALID LOGICAL UNIT (input).
• CA Dynam/T makes sure that the specified drive does not contain a tape
that is an active generation of a controlled data set (output).
Protecting Controlled Data Sets
CA Dynam/T does not permit an active tape that is a member of a controlled
data set to be opened for use as an output tape under any circumstances.
When the program issues a CLOSE for the file, CA Dynam/T updates the
Catalog for output-controlled data sets to indicate that a new generation has
been created.
CA Dynam/T Support Exceptions
CA Dynam/T controls and protects data sets through OPEN/CLOSE intercepts.
Therefore, it does not support the following:
• Programs and utility packages that do not open and close files (for
example, DITTO)
• Programs that perform physical I/O operations that violate VSE LIOCS
conventions
CA Dynam/T is designed to process and control IBM standard labeled and
unlabeled tape files. It does not support the following tape files:
• Tape files with nonstandard or user label processing
• DTFMT TYPE=WORK
• Tape files opened as input, then processed as output
Establishing Retention Characteristics
Data set retention characteristics tell CA Dynam the following:
• How long to retain each generation?
• Under what conditions can a generation be scratched?
CA Dynam/T is flexible regarding data set retention. You can use the various
retention methods it provides individually or in combination. You can also
modify individual generations within a data set to allow for exceptional or
permanent retention independent of the characteristics of the data set as a
whole.
2–8 User Guide