SMS-managed GDG data sets can be in any one of the following states:

• ACTIVE
• DEFERRED
• ROLLED-OFF

When restoring a GDG data set to SMS-managed storage, DFSMSdss does one of the following:

• Preallocated restore retains the status of the preallocated generation data set (GDS).
• Restore function places the GDS in DEFERRED status, if the TGTGDS keyword is not specified. DFSMSdss leaves the GDS in DEFERRED status to enable you to (1) roll it back as an ACTIVE generation or (2) leave it as DEFERRED.
• If the TGTGDS keyword is specified, the appropriate status is assigned to the data set as long as the requested target status does not violate rules of the generation data group. The default status of logical and physical data set restore operation is DEFERRED.