The z/OS disk storage environment has a long, complex, and esoteric history that can be confusing, frustrating, and even intimidating to new users coming from other platforms. Yet tracks, cylinders, and especially extents, are still important to z/OS users and storage admins. In this session, we'll try to demystify z/OS disk storage, starting with discussion of the 'round, brown, spinning' physical hardware of old up to the automated, virtualized, solid-state and cloud environment of today and its importance to applications. Speaker(s): Steve Pryor