Data set extent and multi-volume data set handling

When migrating data sets that have multiple extents, zDMF images the target data set to be an exact reflection of the source data set. This means that if the source data set in a migration currently is in six extents, then the target data set is allocated with six identically sized extents.

Similarly, zDMF handles multi-volume data sets in a very similar manner. If a data set spans over five volumes, zDMF ensures that the target data set being migrated is spanned over five volumes with the same number of extents on each volume. If you wish to reduce the number of target volumes, and/or to consolidate extents, you may use the Consolidate All option. For details, see Consolidate all. If you do not wish to migrate all volumes from a multiple volume data set, zDMF allows you to select specific volumes for migration; for details, refer to MIGRATE_ONLY_SPECIFIED_VOLUMES.

z/OS® allows a single data set to have extents on up to 59 volumes. (Under SMS, you only need to supply one volume in the Target Volume(s) field. SMS will select the actual volumes based on your ACS routines.) If more volumes are needed than originally defined on the panel, edit the Group definition using the Modify option to add additional volumes to the Group Definition. Instructions on how to add more target volumes are explained in Modifying a group definition to add more target volumes.