Difficulty: Easy
Correct Answer: can only be accessed serially
Explanation:
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:
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:
Identify storage medium: tape → linear, sequential stream.Evaluate options: only one describes the fundamental access constraint.Eliminate distractors about “meant for backup” (a use case, not an access rule), “cannot be transformed to disk” (it can), and “must be in key sequence” (not required by the medium itself).Select “can only be accessed serially.”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:
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
Discussion & Comments