You can extend an extended-format sequential data set that is allocated with a single stripe to additional volumes. This data set can be a multivolume data set.

An extended-format sequential data set that is allocated with more than one stripe cannot be extended to more volumes. An extended-format sequential data set with multiple stripes has one stripe per volume. A stripe cannot extend to another volume. When the space is filled on one of the volumes for the current set of stripes, the system cannot extend the data set any further.

An extended-format sequential data set can have a maximum of 59 stripes and, thus, a maximum size of 59 volumes. The number of volumes that are available limits the number of stripes for a data set. Although you cannot extend a striped, extended-format sequential data set to new volumes, you can extend the data set on the original volumes. This function allows you to have a much larger extended-format sequential data set. When the system extends the data set, the system obtains space on all volumes for the data set. The system spreads the primary and secondary allocation amounts among the stripes.

Related reading: For information on specifying the sustained data rate in the storage class, which determines the number of stripes in an extended-format sequential data set, see the z/OS DFSMSdfp Storage Administration. For more information on the SPACE parameter, see the z/OS MVS JCL Reference.