Mainframe, MVS and zOS Discussion

Hello,

What is the maximum limit for a GDG generation? In a way, I know this but I'm bit confused - as per the materials available it is 255. But when I have created a new gdg with NOEMPTY, NOSCRATCH option it created more than 258 generations without deleting the previous generations. And all the generations are catalogued. How come?

Thanks

Mathematically, you can have generations numbered up to 9999 as in GxxxxV00 -- "xxxx" can go from 0000 to 9999. However, if you've a GDG for which you've somehow cataloged 9999 generations -- only 255 of them will be 'active" and will be "attached" to the GDG-base.

When you refer to GDGs with relative-generation-numbers, e.g. (+1), +(2) -- only the "active" generations will be referred.

Just a side note -- You should also read about SCRATCH, EMPTY, NOEMPTY for GDGs.

Thanks Anuj, this is helpful.

You're welcome!