Using EXPORT and IMPORT for Backup and Recovery of VSAM Data Sets

Using EXPORT/IMPORT for backup and recovery has the following advantages:

Key-sequenced data set or variable-length RRDS is reorganized. Using EXPORT for backup results in data reorganization and the recreation of an index for a key-sequenced data set or variable-length RRDS. The data records are rearranged physically in ascending key sequence and free-space quantities are balanced. (Control interval and control area splits can have placed the records physically out of order.) When a key-sequenced data set is reorganized, absolute references using the RBA are no longer valid.
Redefinition is easy. Because most catalog information is exported along with the data set, you are not required to define a data set before importing the copy. The IMPORT command deletes the original copy, defines the new object, and copies the data from the exported copy into the newly defined data set.
Attributes can be changed or added. When you IMPORT a data set for recovery, you can specify the OBJECTS parameter to show new or changed attributes for the data set. Importing a data set lets you change the name of the data set, the key ranges, the volumes on which the data set is to reside, and the SMS classes. For information about accessing a data set using RLS, see Using VSAM Record-Level Sharing.