# Defining a generation data group

You can define a new generation data group from the Remote Systems view.

Before you begin
You need to be connected to a z/OS system.
About this task
To define a new generation data group in the Remote Systems view, do these steps:

1. Select MVS Files and then click Define Generation Data Group on the pop-up menu. The Define Generation Data Group window opens.
2. Complete the fields on this window as follows:
   Name
     Specify a name for the GDG.
   Limit
     Specify the maximum number, from 1 to 255, of GDSs that can be associated with the GDG.
   Empty flag
     Specify the action to be taken for the catalog entries for the GDG base when the number of generation data sets in the GDG base is equal to the limit value and another GDS is to be cataloged. The disposition of the actual data sets uncataloged from the GDG base is determined by the setting of the Scratch flag parameter for the GDG base. If the Empty flag is set, all GDS entries are removed from GDG base when creating a new GDS causes the GDG limit to be exceeded. Otherwise, only the oldest GDS entry is removed.
   Owner
     Identify the generation data set's owner. If this parameter is not specified, the user ID is the default owner ID.
   Scratch flag
     Specify the action is to be taken for a GDS when the data set is uncataloged from the GDG base as a result of empty processing. If the flag is set, the GDS is deleted from all disks it occupies when uncataloged from the GDG base, regardless of whether it is SMS-managed or not. Otherwise, if the data set is a non-SMS managed data set it is not removed from any of the volumes it occupies, and if the data set is an SMS-managed data set it is recataloged as a non-VSAM data set, and is no longer associated with the GDG base. It is not deleted from any of the SMS-managed volumes it occupies.
   Retention Period
     Specify the retention period for the generation data group being defined, in the form of either [yyyy/]mm/dd or days up to 9999. If not specified, the generation data group can be deleted at any time.
3. Click OK to define the new generation data group.

Parent topic: Viewing and working with generation data groups