Xiafs was a file system for the

Linux kernel The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ope ...

which was conceived and developed by Frank Xia and was based on the

MINIX file system The Minix file system is the native file system of the Minix operating system. It was written from scratch by Andrew S. Tanenbaum in the 1980s and aimed to replicate the structure of the Unix File System while omitting complex features, and was ...

. Today it is obsolete and not in use, except possibly in some historic installations.

History

Linux originally used the MINIX file system, but it had a number of limitations. For example, the length of filenames was limited to 14 characters and the partition size was limited to 64 MB. To replace the MINIX file system, the

extended file system The extended file system, or ext, was implemented in April 1992 as the first file system created specifically for the Linux kernel. It has metadata structure inspired by traditional Unix filesystem principles, and was designed by Rémy Card to ove ...

(or ext) was developed. However, ext retained some problems such as poor performance and the lack of some date stamps. Two contenders for replacing ext were quickly developed:

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

and Xiafs. The two file systems were included in the standard kernel in December 1993 (

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

0.99.15).

and Xiafs had the same goal: To offer good performance, reasonable limitations, and fixing the flaws of

ext Ext, ext or EXT may refer to: * Ext functor, used in the mathematical field of homological algebra * Ext (JavaScript library), a programming library used to build interactive web applications * Exeter Airport (IATA airport code), in Devon, England ...

. Initially, Xiafs was more stable than ext2, but being a fairly minimalistic modification of the MINIX file system, it was not very well suited for future extension. The end result was that Xiafs changed very little while ext2 evolved considerably, rapidly improving stability and performance, and adding extensions. ext2, after some shakedown time, quickly became the standard file system of Linux. Since then, ext2 has developed into a very mature and robust file system. Xiafs and the original ext were removed from

version 2.1.21, as they were no longer in use and were not maintained.

ext3 ext3, or third extended filesystem, is a journaled file system that is commonly used by the Linux kernel. It used to be the default file system for many popular Linux distributions. Stephen Tweedie first revealed that he was working on extend ...

, and their successor

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 ...

are in the Linux kernel. As an exercise in computer history and as a file system tutorial, Xiafs was ported to modern Linux in 2013.Porting an Ancient Filesystem to Modern Linux
Jeremy Bingham

Comparison with ext2

Xiafs was less powerful and offered less functionality than ext2. The maximum size of a file was 64 MiB and the maximum size of a partition was 2 GiB. While this was an improvement over ext, it did not measure up to ext2. Xiafs used less disk space for its control structures and it had greater stability at that time.

External links

A modern implementation of Xiafs

References

{{File systems Disk file systems File systems supported by the Linux kernel

History

Comparison with ext2

See also

External links

References