Hardware Reference
In-Depth Information
❍
etc
—his stores miscellaneous configuration files, including the list of users and their
encrypted passwords.
❍
home—
Each user gets a subdirectory beneath this directory to store all their personal
iles.
❍
lib
—his is a storage space for
libraries
, which are shared bits of code required by
numerous different applications.
❍
lost+found
—his is a special directory where
file fragments
are stored if the system
crashes.
❍
media
—his is a special directory for removable storage devices, like USB memory
sticks or external CD drives.
❍
mnt—
his folder is used to manually
mount
storage devices, such as external hard drives.
❍
opt—
his stores optional software that is not part of the operating system itself. If
you install new software to your Pi, it will usually go here.
❍
proc
—his is another virtual directory, containing information about running pro-
grams, which are known in Linux as
processes
.
❍
selinux
—Files related to
Security Enhanced Linux
, a suite of security utilities originally
developed by the US National Security Agency.
❍
sbin
—his stores special binary files, primarily used by the root (superuser) account
for system maintenance.
❍
sys
—his directory is where special operating system files are stored.
❍
tmp
—Temporary files are stored here automatically.
❍
usr
—his directory provides storage for user-accessible programs.
❍
var
—his is a virtual directory that programs use to store changing values or
variables
.
Physical Layout
Although the preceding list is how the file system appears to the Linux operating system, it's
not how it's laid out on the SD card itself. For the default Raspbian distribution, the SD card is
organised into two main sections, known as
partitions
because they split the device into differ-
ent areas in much the same way as the chapters of this topic help to organise its contents.
The first partition on the disk is a small (approximately 75 MB) partition formatted as VFAT,
the same partition format used by Microsoft Windows for removable drives. This is
mounted
,
or
made accessible, by Linux in the
/boot
directory and contains all the files required to
configure the Raspberry Pi and to load Linux itself.
