Magnetic tape storage fundamentals: How can records in a tape file be accessed during normal operations?

Introduction / Context:
Magnetic tape remains relevant for archival storage and large sequential workloads. Understanding its access characteristics helps choose the right medium for backup, restore, and offline processing, and explains why tapes are different from random-access disks or SSDs.

Given Data / Assumptions:

• Tape data is stored along linear tracks and read by streaming past a head.
• We are considering typical operational access patterns, not specialized indexing robots.
• We need to identify the intrinsic access mode of tape files.

Concept / Approach:
Magnetic tape supports sequential access: to reach record N, the device advances past prior records. This contrasts with disk/SSD random access, which can seek directly to a block. Tape excels at long, contiguous reads/writes with low cost per terabyte, but it is unsuitable for workloads requiring frequent, small, random retrievals.

Step-by-Step Solution:

Verification / Alternative check:
Vendor documentation for LTO and legacy tape systems emphasizes streaming performance and sequential access; random seeks are extremely slow and effectively impractical for interactive retrieval.

Why Other Options Are Wrong:

• Are meant for backup: Often used for backup, but not a defining property.
• Cannot be transformed to a disk file: False; tapes are commonly restored to disk.
• Have to be arranged in a key sequence: Not an inherent tape requirement.
• None: Incorrect because sequential-only access is correct.

Common Pitfalls:
Expecting disk-like random reads on tape; overlooking staging strategies (restore to disk cache for random work).

Final Answer:
can only be accessed serially