Notes - Chapter 12: Mass Storage System

Chapter 12: Mass Storage System

Created: 2025-12-16

Updated: 2025-12-16

Disk Structure

disk drives are addressed as large 1-dim arrays of logical blocks
platter -- track -- sector
logical block (sector) mapped onto disk sequentially
- Sector 0: Platter 0, Track 0, Sector 0
- go from outermost track to innermost track
Sector Per Track
- CLV (Constant Linear Velocity)
  - density of bits per track is uniform, keep same data rate
  - rotational speed varies; the inner, the faster
- CAV (Constant Angular Velocity)
  - rotational speed is constant
  - density varies; the inner, the higher