The Basics Of The File System

A computer's file system, sometimes written as a filesystem, is how files are named and where they are stored and retrieved logically. Without a file system, the saved information wouldn't be separated into separate files, making it hard to find and get back. As the amount of data that can be stored grows, it becomes even more critical that files are organized and easy to find.

Digital file systems and files are named and designed after paper-based filing systems, using the exact logic-based mechanism for storing and retrieving information.

Different operating systems (OS), such as Microsoft Windows, macOS, and Linux-based systems, can have other file systems. Some file systems are made to work with specific programs. Distributed file systems, disk-based file systems, and unique-purpose file systems are the main types of file systems.

File systems: how they work

A file system is a way to store and organize data. It can be considered an index for all the information on a storage device. These devices are hard drives, CD/DVD drives, and flash drives.

File systems have rules about how to name files, such as how many characters can be in a name, which characters can be used, and, in some systems, how long the last part of a file name can be. In many file systems, the case of the name of a file doesn't matter.

In addition to the file itself, file systems also store information about its attributes, location, and hierarchy in the directory. This information is called metadata. Metadata can also find free storage blocks on a drive and tell how much space is free.

File systems and how metadata works

File systems use metadata to store and find files. Examples of metadata tags include:

        Date Creation

        Date modified

        Last of access

        User ID of the file creator

        File size

Metadata is kept separate from the file's content. Many file systems keep the file names in their directory entries. Some metadata can be held in the directory, while others can be kept in a structure called an inode.

In operating systems like Unix, an inode can store metadata that has nothing to do with the file itself. The inode keeps track of information by number, which can be used to get to the file's location and then the file itself.

OS X, Apple's operating system, is an example of a file system that uses metadata. It has several ways to improve performance, such as file names that can be up to 255 characters long.

Use of the file system

File systems can also limit who can read or write to a particular group of people. Passwords are the uncomplicated way to do this. By limiting access, you can control who can change or read files and ensure that data changes are limited and controlled.

Access to the file system can also be limited by using file permissions like access or capability control lists. These security measures can stop regular users from getting in, but they don't work as well against people who break-in from the outside.

Encrypting files can also stop users from opening them, but the main goal is to protect systems from attacks from the outside. A key can be used to encrypt text that is not already encrypted, or it can be used to decrypt text that has already been encrypted. The file can only be unlocked by people who have the key. When data is encrypted, the file system doesn't need to know the encryption key to handle the information well.

File system types

There are different file systems, each with structure and properties, like speed and size. The file system type can vary based on the OS and what it needs. Microsoft Windows, Mac OS X, and Linux are the three most-used PC operating systems. Apple iOS and Google Android are two examples of mobile OSes.

Some essential file systems are:


The Microsoft Windows OS can work with FAT. FAT is thought to be easy to use and reliable, and it is based on older file systems. FAT was made for floppy disks in 1977, but it was later changed to work with hard disks. Even though FAT works well and is compatible with most operating systems today, it can't keep up with the speed and scalability of more modern file systems.

Global file system (GFS)

GFS is a standard disk file system for the Linux operating system. GFS can be used as a local file system and gives you direct access to shared block storage.

GFS2 is a newer version than GFS. It has features that GFS didn't have before, like a unique metadata system. The GNU General Public License says that the GFS and GFS2 file systems can be used for free.

A file system with a hierarchy (HFS)

HFS was made so that Mac operating systems could use it. HFS is also called Mac OS Standard, and Mac OS Extended is what came after it. The original Macintosh file system was replaced by HFS, which came out in 1985 for both floppy and hard disks. It can be used on CD-ROMs as well.

New File System Based on Technology

The New Technology File System (NTFS), also called the NT file system, is the default file system for Windows products starting with Windows NT 3.1 OS. Compared to the old FAT file system, this one has better support for metadata, performance, and use of disk space. Thanks to a free, open-source NTFS driver, the Linux OS also works with NTFS. NTFS can be used on Mac OSes, but only to read files.

Universal Disk Format (UDF)

UDF is a file system that can be used on CDs, DVDs, and other optical media. The UDF file system has replaced the ISO 9660 file system. The DVD Forum chose UDF as the official file system for DVD video and audio.

File system vs. DBMS

A database management system (DBMS), like a file system, stores data in a way that makes it easy to update and get back. But you can't switch between the two. A file system stores unorganized and often unrelated files, while a database management system (DBMS) stores and manages organized and related data.

A DBMS makes a database and tells it what it can and can't do. A file system lets you open one file at a time and gives each file its address. Because of this, functions like redundancy are not done by the file system itself but by each file. Because of this, a file system is a much less reliable way to store data than a database management system (DBMS), which keeps one repository of data that is only defined once.

The centralized structure of a database management system (DBMS) makes it easier to share files than a file system and prevents problems that can happen when changes are made to different files in a file system.

There are ways to protect files in a file system, but a DBMS is the way for heavy-duty security. The OS is in charge of a file system's safety, and keeping it up to date can be problematic as users access files and get permission to do things.

A DBMS keeps security restrictions high with passwords, encryption, and limited permissions. More security does make it harder to get data, so a file system may be better for storing and getting files in a general way that is easy to use.

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