Linux File Systems

Note: Cluster and distributed file systems will not be included for simplicity.

1) ext (Extended File System): 

Implemented in 1992, it is the first file system specifically designed for Linux. It is the first member of the ext family of file systems.

2) ext2: 

The second ext was developed in 1993. It is a non-journaling file system that is preferred to be used with flash drives and SSDs. It solved the problems of separate timestamp for access, inode modification and data modification. Due to not being journaled, it is slow to load at boot time.

3) Xiafs: 

Also developed in 1993, this file system was less powerful and functional than ext2 and is no longer in use anywhere.

4) ext3: 

The third ext developed in 1999 is a journaling file system. It is reliable and unlike ext2, it prevents long delays at system boot if the file system is in an inconsistent state after an unclean shutdown. Other factors that make it better and different than ext2 are online file system growth and HTree indexing for large directories.

5) JFS (Journaled File System):

First created by IBM in 1990, the original JFS was taken to open source to be implemented for Linux in 1999. JFS performs well under different kinds of load but is not commonly used anymore due to the release of ext4 in 2006 which gives better performance.

6) ReiserFS: 

It is a journal file system developed in 2001. Despite its earlier issues, it has tail packing as a scheme to reduce internal fragmentation. It uses a B+ Tree that gives less than linear time in directory lookups and updates. It was the default file system in SUSE Linux till version 6.4, until switching to ext3 in 2006 for version 10.2.

7) XFS: 

XFS is a 64-bit journaling file system and was ported to Linux in 2001. It now acts as the default file system for many Linux distributions. It provides features like snapshots, online defragmentation, sparse files, variable block sizes, and excellent capacity. It also excels at parallel I/O operations.

8) SquashFS: 

Developed in 2002, this file system is read-only and is used only with embedded systems where low overhead is needed.

9) Reiser4: 

It is an incremental model to ReiserFS. It was developed in 2004. However, it is not widely adapted or supported on many Linux distributions.

10) ext4: 

The fourth ext developed in 2006, is a journaling file system. It has backward compatibility with ext3 and ext2 and it provides several other features, some of which are persistent pre-allocation, unlimited number of subdirectories, metadata checksumming and large file size. ext4 is the default file system for many Linux distributions and also has compatibility with Windows and Macintosh.

11) btrfs (Better/Butter/B-tree FS): 

It was developed in 2007. It provides many features such as snapshotting, drive pooling, data scrubbing, self-healing and online defragmentation. It is the default file system for Fedora Workstation.

12) bcachefs: 

This is a copy-on-write file system that was first announced in 2015 with the goal of performing better than btrfs and ext4. Its features include full filesystem encryption, native compression, snapshots, and 64-bit check summing.

13) Others:

 Linux also has support for file systems of operating systems such as NTFS and exFAT, but these do not support standard Unix permission settings. They are mostly used for interoperability with other operating systems.

Operating systems, the software that powers your computer, rely on a crucial element known as the file system. Think of it as a virtual organizational tool that manages, stores, and retrieves your data efficiently. In the Linux world, a diverse range of file systems has emerged, each crafted to address specific needs and preferences. This article aims to simplify the intricacies of Linux file systems, guiding beginners through their layers, characteristics, and implementations. By shedding light on these nuances, we empower users to make informed choices in navigating the dynamic landscape of Linux operating systems.