# Welcome to iDefrag’s documentation!

Thank-you for purchasing iDefrag, our defragmenter and disk optimiser. We think you’ll love the product, and we hope that you find the documentation helpful and easy to follow. If you find any mistakes, or find anything confusing or hard to understand, please let us know and we’ll try to help.

If you haven’t used iDefrag before, we recommend that you start by reading the Getting Started section before you try to use the program.

Contents:

- What’s New?
- Why Defragment?
- Getting Started
  - About your license
  - Before you start
  - Authorisation
  - Main display
  - Defragmenting your boot disk
  - How can I tell if my disk needs defragmenting?
  - How long does a typical defragmentation take?
  - What should I do if something goes wrong?
- Filesystems and Disks
  - Introduction
  - About your hard disk
  - Filesystems, volumes and partitions
  - SimpleFS - a worked example
- Algorithms
  - Full Defrag
  - Optimize
  - Metadata
  - Compact
  - Quick (on-line)
  - Selected Files (on-line)
- Class Sets
  - Built-in classes
  - Default classes
  - Writing your own class set
  - Class set syntax
  - Reference information
- Information Pane
  - Filesystem information
  - Block view key
  - File information
- Credits
  - iDefrag 5
  - Documentation
- iDefrag License Agreement
  - Normal license
  - Workshop license
  - Site license
  - General terms