Hard Disk Geometry and Low-Level Data Structures

When this guide was first written around the year 2000, the most advanced hard drives were capable of storing 20GB per platter. Now in 2010 and beyond, drives can store in excess of 375GB per platter -- and that number is only going up!

In order to use all this real estate to best advantage, special methods have evolved for dividing the disk up into usable pieces. The goals, as usual, are two-fold: increasing capacity and increasing performance. This section takes a detailed look at how information is encoded, stored, retrieved and managed on a modern hard disk. Many of the descriptions in this section in fact form the basis for how data is stored on other media as well.

Next: Data Encoding and Decoding