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Chapter 1. File System Structure

1.2.1. FHS Organization

The directories and files noted here are a small subset of those specified by the FHS document. Check

the latest FHS document for the most complete information.

1.2.1.1. The

/dev

Directory

The

/dev

directory contains file system entries which represent devices that are attached to the system.

These files are essential for the system to function properly.

1.2.1.2. The

/etc

Directory

The

/etc

directory is reserved for configuration files that are local to your machine. No binaries are

to be put in

/etc

. Any binaries that were formerly put in

/etc

should now go into

/sbin

or possibly

/bin

.

The

X11

and

skel

directories are subdirectories of the

/etc

directory:

/etc

|  X11

|  skel

The

X11

directory is for X11 configuration files such as

XF86Config

. The

skel

directory is for

"skeleton" user files, which are used to populate a home directory when a user is first created.

1.2.1.3. The

/lib

Directory

The

/lib

directory should contain only those libraries that are needed to execute the binaries in

/bin

and

/sbin

. These shared library images are particularly important for booting the system and

executing commands within the root file system.

1.2.1.4. The

/mnt

Directory

The

/mnt

directory is for temporarily mounted file systems, such as CD ROMs and floppy disks.

1.2.1.5. The

/opt

Directory

The

/opt

directory provides an area for large, static application software packages to be stored.

For packages that wish to avoid putting their files throughout the file system,

/opt

provides a logical

and predictable organizational system under that package's directory. This gives the system adminis 

trator an easy way to determine the role of each file within a particular package.

For example, if

sample

is the name of a particular software package located within

/opt

, then all

of its files could be placed within directories inside

/opt/sample

, such as

/opt/sample/bin

for

binaries and

/opt/sample/man

for manual pages.

Large packages that encompass many different sub packages, each of which accomplish a particular

task, also go within

/opt

, giving that large package a standardized way to organize itself. In this

way, our

sample

package may have different tools that each go in their own sub directories, such as

/opt/sample/tool1

and

/opt/sample/tool2

, each of which can have their own

bin

,

man

, and

other similar directories.