# ReiserFS

> file system

**Wikidata**: [Q687074](https://www.wikidata.org/wiki/Q687074)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/ReiserFS)  
**Source**: https://4ort.xyz/entity/reiserfs

## Summary
ReiserFS is a journaling file system designed for Linux, developed by Namesys and named after its creator, Hans Reiser. It was widely used in early Linux distributions for improved performance and reliability through journaling. ReiserFS is notable for being succeeded by Reiser4.

## Key Facts
- **Instance of**: Journaling file system
- **Developer**: Namesys, led by Hans Reiser
- **License**: GNU General Public License
- **Operating System**: Linux
- **Succeeded by**: Reiser4 (inception: 2004)
- **Version**: 5.7.1
- **Aliases**: Reiser File System
- **Partition Identifiers**:
  - GUID: EBD0A0A2-B9E5-4433-87C0-68B6B72699C7
  - MBR: 0x83
- **Named After**: Hans Reiser
- **Different From**: Reiser4

## FAQs
### Q: What is ReiserFS used for?
A: ReiserFS is a journaling file system for Linux that improves data integrity and recovery speed after crashes by using a journal to track uncommitted changes.

### Q: Who created ReiserFS?
A: ReiserFS was created by Hans Reiser and his company Namesys, which was based in Oakland, United States.

### Q: Is ReiserFS still in use today?
A: While once popular, ReiserFS has largely been superseded by newer file systems like Reiser4 and others such as ext4 and XFS in modern Linux systems.

## Why It Matters
ReiserFS played a significant role in the evolution of Linux storage systems by introducing efficient metadata handling and journaling capabilities. As one of the earlier journaling file systems adopted in Linux, it offered enhanced performance and reliability over traditional non-journaling systems like ext2. Its design influenced future developments in file system architecture, particularly in balancing speed and data consistency. Though now largely replaced, ReiserFS represented a key step forward in making Linux more robust for enterprise and desktop use during the early 2000s.

## Notable For
- Being one of the first high-performance journaling file systems integrated into Linux
- Introduction of balanced tree structures for metadata organization, improving file access times
- Support from organizations such as MP3.com, DARPA, and Linspire
- Pioneering innovations later refined in its successor, Reiser4
- Strong association with Hans Reiser, a prominent figure in filesystem development

## Body
### Overview
ReiserFS is a journaling file system for Linux, developed by Namesys under the leadership of Hans Reiser. It was designed to improve performance and reliability by implementing journaling techniques that reduce the risk of data corruption following unexpected system failures.

### Development and History
- **Created by**: Namesys, a U.S.-based IT company headquartered in Oakland
- **Inception**: Early 2000s; became part of mainstream Linux kernel around 2001–2002
- **Named after**: Hans Reiser, founder of Namesys and lead developer
- **Successor**: Reiser4, released in 2004

### Technical Features
- **Journaling mechanism**: Tracks pending disk writes in a journal to allow fast recovery after crashes
- **Metadata structure**: Uses balanced trees (similar to B+ trees) for organizing file metadata, enabling faster directory operations and small file handling
- **Partition identifiers**:
  - GUID Partition Table (GPT): `EBD0A0A2-B9E5-4433-87C0-68B6B72699C7`
  - Master Boot Record (MBR): Hex code `0x83`

### Licensing and Distribution
- **License**: GNU General Public License (GPL)
- **Supported OS**: Primarily Linux
- **Included in**: Various Linux distributions including SuSE, Linspire, and others in the early 2000s

### Versioning
- **Latest known version**: 5.7.1
- **Distribution platforms**: Available via SourceForge and other open-source repositories

### Legacy and Decline
- **Superseded by**: Reiser4 and other modern file systems like ext4, XFS, and Btrfs
- **Current status**: No longer actively maintained or widely deployed in production environments
- **Differentiation**: Explicitly distinct from Reiser4 in both implementation and lineage

### Community and Documentation
- **Wikipedia languages**: Available in multiple languages including English, French, Japanese, Hungarian, German, Spanish, and others
- **Documentation presence**: Covered in Gentoo Wiki and Pro Linux database (ID: 126)

## References

1. [Source](https://sourceforge.net/projects/reiser4/files/reiser4-for-linux-5.x/)
2. Freebase Data Dumps. 2013
3. Quora