The Storage Management Subsystem (SMS) is an operating environment that automates the management of storage. Storage management uses the values provided at allocation time to determine, for example, on which volume to place your data set, and how many tracks to allocate for it. Storage management also manages tape data sets on mountable volumes that reside in an automated tape library. With SMS, users can allocate data sets more easily.

The data sets allocated through SMS are called system-managed data sets or SMS-managed data sets. For information about allocating system-managed data sets, see Using the Storage Management Subsystem. If you are a storage administrator, also see z/OS DFSMSdfp Storage Administration for information about using SMS.