This page describes the typical layout of a modern hard drive. You may have heard of file systems such as NTFS, FAT32 or EXT3, which are used by your operating system. Concepts like files and directories are contained in these file systems, so obviously they are very important. But a single physical hard disk can contain multiple filesystems – each on a separate partition. And a hard disk that contains a operating system must contain some elements that play a role in the boot sequence.
Obviously a lot more is going on under the hood. Let’s take a look.
Anatomy of a hard disk
Hard disks have been around since the 1950′s, but the design has not changed much. The general hard disk design is quite simple, consisting of only a few moving parts. In the picture above you can see:
- Platters: Solid disks with a magnetic coating that contains the data. The platters spin at a constant rate when the hard disk is in operation, typically at 3600, 5200 or 7200 rounds per minute (rpm).
- Arms: The head stack assembly holds the arms that hold the read/write heads. The stack is rotated by an actuator which is not displayed in the image, causing the arms to position the heads between