Drive

Enhanced Definition

In the mainframe context, a **drive** refers to a physical or logical storage unit, primarily a Direct Access Storage Device (DASD) or a tape drive, used to store data volumes. It serves as the fundamental hardware component for persistent data storage, accessible by the z/OS operating system and its applications.

Key Characteristics

- Types: Predominantly DASD (e.g., IBM DS8000 series, often referred to as disk drives) for online, random access data, and tape drives (e.g., IBM TS7700 Virtual Tape Library, TS3500 physical tape drives) for sequential access, backup, and archival.
- Logical Abstraction: While physical drives exist, z/OS often interacts with logical volumes presented by storage controllers, especially with DASD, allowing for advanced features like data mirroring and virtualization.
- Addressing: Each drive or logical volume is identified by a unique device number (e.g., 0A80) and, for DASD, a volume serial number (e.g., PROD01), which is stored on the volume's Volume Table of Contents (VTOC).
- **Connectivity