Disk performance and file layout: Which description best defines a fragmented hard drive in terms of how files are stored on disk?

Introduction / Context:
File-system fragmentation affects performance by scattering file data across the disk, increasing seek time. Understanding what fragmentation is (and isn’t) helps in diagnosing slow systems and applying the correct remedy.

Given Data / Assumptions:

• Conventional spinning hard drive with cluster-based file system (e.g., FAT/NTFS).
• Symptoms: slower file access and longer boot times.
• No evidence of physical drive failure is assumed.

Concept / Approach:

Fragmentation means file data is split into multiple non-contiguous extents. The disk head must perform additional seeks to assemble a file, degrading throughput. This is a logical layout issue, not necessarily data corruption or platter damage.

Step-by-Step Solution:

Verification / Alternative check:

OS defragmenters visualize files as many fragments. After defrag, the same files occupy longer contiguous runs, reducing head movement and improving access times.

Why Other Options Are Wrong:

• Corrupted files: integrity issue, not fragmentation definition.
• Damaged platters or all clusters damaged: indicates hardware faults, not fragmentation.
• None of the above: incorrect because one option precisely matches the definition.

Common Pitfalls:

Confusing fragmentation with bad sectors; thinking SSDs need defrag (they do not benefit and may wear unnecessarily; they use TRIM and wear-leveling instead).

Final Answer:

Files are not stored in consecutive clusters on the disk