All of the major computer operating systems (OS) have their own, proprietary file system that forms the basic architecture for their data storage needs. Essentially, it's the file system that's responsible for labeling raw data into specific files and folders. It identifies each piece of data and allows the OS to easily find a specific file or location when it is needed.

While legacy versions of Windows used the FAT (File Allocation Table) file system, newer versions almost exclusively use NTFS (New Technology File System). Modern Mac computers generally use APFS (Apple File System), although HRS (Hierarchical File System) is sometimes used. Likewise, the Linux OS also has a file system of its own – Ext FS, also known as the extended file system or ext.

History of the extfs
Linux's extfs was introduced in 1992. Officially recognized as the very first file system to be developed for the Linux kernel, it immediately caught on amongst Linux users. It's still in use today – albeit in its fourth generation – and commonly known as ext4.

The extfs was originally commended for its support of large-capacity drives which, at the time, included drives up to 2TB. Now that it's in its fourth iteration, the extfs has a maximum volume size of 1 EiB (exbibyte). As such, ext4 is now the default file system for many of the most popular Linux distros, including Ubuntu, Debian, and more. It's also used in version 2.3 of the Android OS and within Google's own infrastructure.

Primary Features of the extfs
Users of the most up-to-date ext4 file system benefit from a plethora of features, including:

• Flexible storage: Not only does ext4 support a max volume size of 1 EiB, but it supports single files up to 16 TiB (tebibytes) in size.
• Backward compatibility: Newer iterations of the extfs are backward-compatible with prior versions, with the exception of ext1. Additionally, ext3 features partial forward-compatibility with ext4.
• Data allocation: Linux's ext4 uses numerous advanced data allocation techniques, including persistent pre-allocation, delayed allocation, and multiblock allocation, which ultimately increase system speed, efficiency, and reliability.
• Journal checksums: In addition to metadata checksumming, ext4 also uses checksums within the disk's journal. It improves overall system reliability and provides a slight boost to performance.

The fourth iteration of the extfs includes some other useful features, too, such as decreasing the amount of time it takes to check the file system for potential errors, support for transparent encryption, improved file timestamps, and more.

Future of the extfs
Having seen so many updates, upgrades, and bug fixes throughout the years, it's safe to say that Linux's extfs is here to stay – at least for a little while longer. The fact that the file system was last updated in 2006 with the release of ext4 doesn't seem to sway Linux proponents – and who could blame them? After all, ext4 is more than enough to meet the needs of modern computing for years to come.

You may read more about the ext file system in Wikipedia: ext4.
Our article Data Recovery from a Re-Formatted Ext2/3/4FS Disk explains how to recover files from such disks.