An Introduction to Disk Partitions
This appendix is not necessarily applicable to architectures other than AMD64 and Intel{nbsp}64. However, the general concepts mentioned here may apply.
This section discusses basic disk concepts, disk repartitioning strategies, the partition naming scheme used by Linux systems, and related topics.
If you are comfortable with disk partitions, you can skip ahead to xref:sect-disk-partitions-making-room[Strategies for Disk Repartitioning] for more information on the process of freeing up disk space to prepare for a {PRODUCT} installation.
Hard Disk Basic Concepts
Hard disks perform a very simple function - they store data and reliably retrieve it on command.
When discussing issues such as disk partitioning, it is important to have a understanding of the underlying hardware; however, since the theory is very complicated and expansive, only the basic concepts will be explained here. This appendix uses a set of simplified diagrams of a disk drive to help explain what is the process and theory behind partitions.
xref:figu-partitions-unused-drive[An Unused Disk Drive], shows a brand-new, unused disk drive.
An Unused Disk Drive
Image of an unused disk drive.
File Systems
To store data on a disk drive, it is necessary to _format_ the disk drive first. Formatting (usually known as "making a _file system_pass:attributes[{blank}]") writes information to the drive, creating order out of the empty space in an unformatted drive.
Disk Drive with a File System
Image of a formatted disk drive.
As xref:figu-partitions-formatted-drive[Disk Drive with a File System], implies, the order imposed by a file system involves some trade-offs:
A small percentage of the driver's available space is used to store file system-related data and can be considered as overhead.
A file system splits the remaining space into small, consistently-sized segments. For Linux, these segments are known as _blocks_ footnote:[Blocks really *are* consistently sized, unlike our illustrations. Keep in mind, also, that an average disk drive contains thousands of blocks. The picture is simplified for the purposes of this discussion.].
Note that there is no single, universal file system. As xref:figu-partitions-different-file-system[Disk Drive with a Different File System], shows, a disk drive may have one of many different file systems written on it. Different file systems tend to be incompatible; that is, an operating system that supports one file system (or a handful of related file system types) may not support another. However, {PRODUCT} supports a wide variety of file systems (including many commonly used by other operating systems such as Microsoft Windows), making data interchange between different file systems easy.