Chapter 7. File Tree Organization

Shareable/Unshareable, Static/Variable Data
The root Directory: /
/usr: The Big One
/var: Modifiable Data During Use
/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 there were not any guidelines for the location of files in the tree.

The acknowledged standard is the FHS (Filesystem Hierarchy Standard), which at the time this manual was written was at version 2.2 and discussions have started for version 2.3. 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 teach you which directory is likely to contain a given file, or where a given file should be placed into.