Chapter 7. File-Tree Organization

1. Shareable/unshareable, Static/Variable Data
2. The root Directory: /
3. /usr: The Big One
4. /var: Data Modifiable During Use
5. /etc: Configuration Files

Nowadays, a UNIX® system is big, very big. This is especially true of GNU/Linux: the amount of software available would make for an unmanageable system if no guidelines for the location of files in the tree existed.

The acknowledged standard is the FHS (Filesystem Hierarchy Standard) for which version 2.3 was released in January 2004. The document which describes the standard is available on the Internet in different formats on The Pathname web site. This chapter will only provide a brief summary, but it should be enough to show you which directory is likely to contain a given file, or where a given file should be placed.