I have a GDG version
What do you mean by this? You are mixing various terms.
Can I do this throgh JCL?
Why not - almost everything on the mainframe runs because it has JCL - batch jobs, TSO, CICS, IMS etc.
Are you talking about one GDG base or several? Is one generation created per run or several.
NOTE: there is nothing magical about a GDG - it is just an ordinary dataset of its type with a special naming convention.
You have several options:
1 - If you create one new dataset per base per run then your backup control cards could specify generation (0) - may depend on what backup software you use
2 - instead of creating the datasets as GDGs at the start you can crete them with temporary names, back these up and then copy them to their (+1) names.
3 - If you have multiple datasets per GDG per run then you could run a LISTCAT and parse the output to generate the backup control cards. There are several topics on this in the forums.
The problem I have is that people can explain things quickly but I can only comprehend slowly.
Regards
Nic