Moving multivolume data sets

If you are specifying input volumes with the LOGINDDNAME or LOGINDYNAM keywords and you are moving multivolume data sets, use the SELECTMULTI keyword on the COPY command. SELECTMULTI allows you to move multivolume data sets in their entirety, even if you do not specify all the volumes on which the data set resides.

When you specify input volumes using the LOGINDDNAME or LOGINDYNAM volume list, a data set is selected based on the following criteria:

When you either specify SELECTMULTI(ALL) or specify input volumes without specifying the SELECTMULTI keyword, all of the volumes that contain a part of a non-VSAM or VSAM cluster must be in the volume list.
For VSAM data sets, the volume list is affected by the use of the SPHERE keyword as follows:
- Specify SPHERE and you must list all parts of the base cluster in the volume list.
- Do not specify SPHERE and you must list all parts of the base cluster and the associated alternate indexes in the volume list.
When you specify SELECTMULTI(ANY), any part of the non-VSAM data set or VSAM base cluster can be on a volume in the volume list.
For VSAM data sets, the volume list is affected by the use of the SPHERE keyword as follows:
- Specify SPHERE and you must list any part of the base cluster in the volume list.
- Do not specify SPHERE and you must list any part of the base cluster and the associated alternate indexes in the volume list.
When you specify SELECTMULTI(FIRST), the volume list must include the volume that contains the first part of either the non-VSAM data set or the primary data component of the base cluster for a VSAM sphere.
For VSAM data sets, the volume list is affected by the use of the SPHERE keyword as follows:
- Specify SPHERE and you must list the volume that contains the first extent of the data component for the base cluster in the volume list.
- Do not specify SPHERE and you must specify the following information in the volume list:
  - The volume that contains the first extent of the data component for the base cluster.
  - The volume that contains the first extent of the data component for the associated alternate indexes.

If a data set is found on more than one specified input volume and the volume sequence numbers match, DFSMSdss cannot determine which data set to select for processing.

You do not need to specify a SELECTMULTI option when you build a list of input volumes with STORGRP. The volume list contains all of the volumes in a storage group.

A multivolume data set can be copied to a single volume or to multiple volumes. For a multivolume data set with a standard user label, only the standard user label on the first volume is copied to the target volumes.

If you do not specify any input volumes, you can move multivolume data sets without any special keywords.

A DFSMSdss logical data set copy operation attempts to ensure that all parts of a multivolume non-VSAM data set exist. In cases where a part of the data set is missing, such as an inadvertent scratching of the VTOC entry on a volume, DFSMSdss issues an error message and discontinues processing the data set.

DFSMSdss cannot process the following non-VSAM data sets because they are missing one or more parts:

Multivolume data sets whose catalog volume order differs from the VTOC volume order
Single-volume data sets with the same name that are cataloged as one multivolume data set
Multivolume data sets whose last volume indicator in the VTOC is not set

Note: When you are copying or restoring multivolume data sets, be aware of the following considerations:

DFSMSdss does not preserve candidate volumes. However, for SMS-managed data sets, if you copy and do not specify any output volumes, DFSMSdss preserves the source volume count. If you copy and do specify the output volumes, DFSMSdss sets the volume count to the number of output volumes specified.
DFSMSdss does not ensure that the copied or restored data set is on the same number of volumes as the original data set, nor does DFSMSdss ensure that the copied or restored data set extents are the same as the original data set. Instead, DFSMSdss tries to allocate the new data set on as few volumes as possible. This may result in the copied or restored data set becoming a single-volume data set.
In addition, DFSMSdss tries to allocate each volume so that all data is contained in a single primary allocation of contiguous space with few, if any, of the secondary allocations being used.