The extended file system, or ext, was implemented in April 1992 as the first file system created specifically for the

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

kernel. Although ext is not a specific file system name, it has been succeeded by

ext2 ext2, or second extended file system, is a file system for the Linux kernel (operating system), kernel. It was initially designed by French software developer Rémy Card as a replacement for the extended file system (ext). Having been designed ...

ext3 ext3, or third extended filesystem, is a journaling file system, journaled file system that is commonly used with the Linux kernel. It used to be the default file system for many popular Linux distributions but generally has been supplanted by ...

, and

ext4 ext4 (fourth extended filesystem) is a journaling file system for Linux, developed as the successor to ext3. ext4 was initially a series of backward-compatible extensions to ext3, many of them originally developed by Cluster File Systems for ...

. It has

metadata Metadata (or metainformation) is "data that provides information about other data", but not the content of the data itself, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive ...

structure inspired by traditional

Unix filesystem In Unix and operating systems inspired by it, the file system is considered a central component of the operating system. It was also one of the first parts of the system to be designed and implemented by Ken Thompson in the first experimental ...

principles, and was designed by

Rémy Card Rémy Card is a French software developer Software development is the process of designing and Implementation, implementing a software solution to Computer user satisfaction, satisfy a User (computing), user. The process is more encompassing ...

to overcome certain limitations of the MINIX file system. It was the first implementation that used the

virtual file system A virtual file system (VFS) or virtual filesystem switch is an abstract layer on top of a more concrete file system. The purpose of a VFS is to allow client applications to access different types of concrete file systems in a uniform way. A VFS ...

(VFS), for which support was added in the Linux kernel in version 0.96c, and it could handle file systems up to 2 gigabytes (GB) in size. ext was the first in the series of extended file systems. In 1993, it was superseded by both

and

Xiafs Xiafs was a file system for the Linux kernel which was conceived and developed by Ge (Frank) Xia and was based on the MINIX file system. Today it is obsolete and not in use, except possibly in some historic installations. History Linux original ...

, which competed for a time, but ext2 won because of its long-term viability: ext2 remedied issues with ext, such as the immutability of

inode An inode (index node) is a data structure in a Unix-style file system that describes a file-system object such as a file or a directory. Each inode stores the attributes and disk block locations of the object's data. File-system object attribu ...

s and fragmentation. First published in

Other extended file systems

There are other members in the extended file system family: *

, the second extended file system. *

, the third extended file system. *

, the fourth extended file system.

References

1992 software Disk file systems File systems supported by the Linux kernel {{Linux-stub

Other extended file systems

See also

References