Among common storage media, which one is inherently sequential-access only (i.e., cannot provide true random access to arbitrary records)?

Introduction / Context:
Data access patterns vary across storage media. Understanding whether a medium supports random access or only sequential access is crucial for system performance planning and archival design.

Given Data / Assumptions:

• 'Sequential access' means data must be read in order until the desired location is reached.
• 'Random access' means the device can reposition quickly to access any block directly.
• Typical devices: floppy disk, hard disk, ROM, and magnetic tape.

Concept / Approach:

Magnetic tape stores data linearly along a long strip. To reach a given record, the tape must be wound forward or backward to that location—this is sequential by nature. Disks (floppy/hard) use addressable tracks and sectors, enabling near-random access. ROM is also random access by address lines.

Step-by-Step Solution:

Verification / Alternative check:

Backup/archival systems based on LTO tape require tape positioning and are optimized for streaming throughput rather than random I/O, confirming sequential semantics.

Why Other Options Are Wrong:

• Floppy/Hard disks: random access via seek and rotational latency.
• ROM: direct addressing supports random fetches.
• Flash drive: solid-state storage with random access.

Common Pitfalls:

Confusing file system behavior over a medium with the medium's physical access method; even if a file is fragmented, disks remain random-access media.

Final Answer:

Magnetic tape