Using ISMF with VSAM Data Sets

ISMF handles VSAM data sets differently from other types of data sets. When you generate a list that contains VSAM data sets, you should understand the following processes:

How VSAM data sets appear in the list
How the last reference date is determined
How COPY, DUMP, and RESTORE work with VSAM data sets.

How VSAM Data Sets Appear in the List

In general, all of the components of a VSAM data set appear in the list. When the list is originally displayed, it is sorted by data set name. If all the components have the same high-level qualifier, they are grouped together in the list. If any of the components have different names, they could appear separately depending on the names of the other data sets in the list.

Specifying a User Catalog

If you generate the list from a user catalog and specify the user catalog in the catalog name, only the data component of the user catalog appears in the list. If you specify '**' as the data set name, both the data component and the cluster appear.

Last Reference Date

The last reference date is based on date stamp processing. However, VSAM provides a date stamp control module that causes date stamp processing to be skipped for VSAM data sets. Because of this, the data set list does not contain last reference dates for VSAM data sets unless you have substituted your own module to perform date stamp processing. For more information about providing a date stamp routine for VSAM data sets, refer to z/OS DFSMS Using Data Sets .

DUMP, RESTORE, and COPY Considerations

Special considerations apply when you generate the list from the Catalog or the VTOC.

If the list is generated from the VTOC,

you can enter COPY, DUMP, and RESTORE against either the data or index component. ISMF tries to find the associated cluster name to perform the line operator or command. However, if the index component name of a user catalog appears in the list, you will not be able to use COPY, DUMP, or RESTORE against this list entry because ISMF cannot locate the index component cluster name. The cluster name is system generated; it is not in the default order of search.

If the list is generated from the catalog,

COPY, DUMP, and RESTORE can only be entered against the cluster name of a VSAM data set.