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Chapter 9

The Operating System

9.1 File system hierarchy

9.1.1 File system Structure

The location of all installed files and directories must comply with the File system Hierarchy

Standard (FHS), version 2.1, except where doing so would violate other terms of Debian Pol 

icy. The version of this document referred here can be found in the

debian policy

pack 

age or on FHS (Debian copy) (

http://www.debian.org/doc/packaging manuals/

fhs/

) alongside this manual (or, if you have the

debian policy

installed, you can try

FHS (local copy) (

file:///usr/share/doc/debian policy/fhs/

)). The latest version,

which may be a more recent version, may be found on FHS (upstream) (

http://www.

pathname.com/fhs/

). Specific questions about following the standard may be asked on

the

debian devel

mailing list, or referred to the FHS mailing list (see the FHS web site

(

http://www.pathname.com/fhs/

) for more information).

9.1.2 Site specific programs

As mandated by the FHS, packages must not place any files in

/usr/local

, either by putting

them in the file system archive to be unpacked by

dpkg

or by manipulating them in their

maintainer scripts.

However, the package may create empty directories below

/usr/local

so that the system

administrator knows where to place site specific files. These directories should be removed on

package removal if they are empty.

Note, that this applies only to directories below

/usr/local

, not in

/usr/local

. Packages

must not create sub directories in the directory

/usr/local

itself, except those listed in FHS,

section 4.5. However, you may create directories below them as you wish. You must not

remove any of the directories listed in 4.5, even if you created them.

Since

/usr/local

can be mounted read only from a remote server, these directories must be