SMS must be active on your system before you can use JCL to define a VSAM data set. Any VSAM data set can be defined using JCL, except for a variable-length RRDS. Defining a VSAM data set using JCL has certain advantages. It takes less time to input and it makes syntax for defining the VSAM data set very similar to that used for accessing it.

DB2 provides striping on partitioned table spaces. Each of the partitions is a separate linear data set. Striping is used to perform parallel I/O concurrently against more than one of these partitions. The benefit of striping is only achievable if multiple partitions do not get allocated on the same volume. You can achieve volume separation without resorting to the storage class guaranteed space allocations on system-managed volumes.

Allocate all of the partitions in a single IEFBR14 job step using JCL. If an adequate number of volumes exist in the storage groups, and the volumes are not above the allocation threshold, the SMS allocation algorithms with SRM will ensure each partition is allocated on a separate volume.

DB2 striping is unrelated to VSAM striping (see Extended-Format VSAM Data Sets). You can use both DB2 striping and VSAM striping for the same set of linear extended format data sets.

Related reading: See Using Job Control Language for VSAM for information about the JCL keywords used to define a VSAM data set. See z/OS MVS JCL Reference and z/OS MVS JCL User's Guide for information about JCL keywords and the use of JCL.