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The Linux filesystem explained

For starters, there is only a single hierarchal directory structure.

Everything starts from the root directory, represented by '/', and then

expands into sub-directories. Where DOS/Windows had various partitions and

then directories under those partitions, Linux places all the partitions

under the root directory by 'mounting' them under specific directories.

Closest to root under Windows would be c:\.

Under Windows, the various partitions are detected at boot and assigned a

drive letter. Under Linux, unless you mount a partition or a device, the

system does not know of the existence of that partition or device. This

might not seem to be the easiest way to provide access to your partitions

or devices but it offers great flexibility.

This kind of layout, known as the unified filesystem, does offer several

advantages over the approach that Windows uses. Let's take the example of

the /usr directory. This directory off the root directory contains most of

the system executables. With the Linux filesystem, you can choose to mount

it off another partition or even off another machine over the network. The

underlying system will not know the difference because /usr appears to be

a local directory that is part of the local directory structure! How many

times have you wished to move around executables and data under Windows,

only to run into registry and system errors? Try moving c:\windows\system

to another partition or drive.

Another point likely to confuse newbies is the use of the frontslash '/'

instead of the backslash '\' as in DOS/Windows. So c:\windows\system would

be /c/windows/system. Well, Linux is not going against convention here.

Unix has been around a lot longer than Windows and was the standard a lot

before Windows was. Rather, DOS took the different path, using '/' for

command-line options and '\' as the directory separator.

To liven up matters even more, Linux also chooses to be case sensitive.

What this means that the case, whether in capitals or not, of the

characters becomes very important. So this is not the same as THIS or ThIs

for that matter. This one feature probably causes the most problems for

newbies.

We now move on to the layout or the directory structure of the Linux

filesystem. Given below is the result of a 'ls -p' in the root directory.

bin/ dev/ home/ lost+found/ proc/ sbin/ usr/

boot/ etc/ lib/ mnt/ root/ tmp/ var/