GATE CS 1998 Q2-9 — I/O Scheduling

Formatting a disk (specifically physical or low-level formatting) is the process of preparing a magnetic storage medium, such as a floppy disk, for data storage.

During this process, the disk controller writes essential control and identification information onto the disk surface:

• It divides the disk surface into concentric circles called tracks, and further divides each track into segments called sectors.
• It writes identification headers (preambles, sector addresses, and sync bytes) and trailers (like CRC for error checking) for each sector so that the read/write head can locate specific physical blocks of data.

Let us evaluate the options:

• Option A: Arranging data contiguously is called defragmentation, not formatting.
• Option B: Writing the directory structure (creating a file system) is part of high-level formatting, which happens after the physical tracks and sectors are established.
• Option C: Erasing data is a consequence of formatting, but not its primary definition.
• Option D: Writing identification information on all tracks and sectors accurately describes the fundamental physical formatting process.