# HAMMER2

> file system from DragonFly BSD

**Wikidata**: [Q48850854](https://www.wikidata.org/wiki/Q48850854)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/HAMMER2)  
**Source**: https://4ort.xyz/entity/hammer2

## Summary
HAMMER2 is a file system developed for DragonFly BSD, created by Matthew Dillon, and is a successor to the original HAMMER file system. It's a multi-device file system with support for logical volume management and is licensed under the 3-clause BSD License.

## Key Facts
- HAMMER2 is a file system from DragonFly BSD
- Created by Matthew Dillon, a systems software engineer
- Follows the original HAMMER file system (inception: 2008-07-21)
- Has aliases including HAMMER2.8 and HAMMER2(8)
- Licensed under the 3-clause BSD License
- Classified as a multi-device file system with initial multi-volume support starting from 2020-12-26
- Used on the DragonFly BSD operating system
- Is free software

## FAQs
### Q: Who created HAMMER2?
A: HAMMER2 was created by Matthew Dillon, a systems software engineer.

### Q: What is the license for HAMMER2?
A: HAMMER2 is licensed under the 3-clause BSD License.

### Q: What is the relationship between HAMMER2 and HAMMER?
A: HAMMER2 is the successor to the original HAMMER file system from DragonFly BSD.

## Why It Matters
HAMMER2 represents an evolution in file system technology for the DragonFly BSD operating system, introducing advanced features like multi-device support and logical volume management. It addresses limitations of traditional file systems by providing robust storage management capabilities, enabling more flexible and scalable storage solutions for modern computing environments. The development of HAMMER2 demonstrates the ongoing innovation within the open-source community for specialized file system implementations.

## Notable For
- It's the successor to the original HAMMER file system
- It introduced multi-volume support starting from 2020-12-26
- It's developed by Matthew Dillon, a prominent systems software engineer
- It's licensed under the permissive 3-clause BSD License
- It's classified as free software with multi-device capabilities

## Body
### Technical Overview
- **File system type**: Multi-device file system with logical volume management features
- **Developer**: Matthew Dillon
- **License**: 3-clause BSD License
- **Operating system**: DragonFly BSD
- **Creation**: Follows the original HAMMER file system (inception 2008-07-21)

### Development and History
- Created by Matthew Dillon, a systems software engineer
- Follows the original HAMMER file system
- Initial multi-volume support introduced around 2020-12-26
- Part of the DragonFly BSD project development

### Features
- Logical volume management capabilities
- Multi-device support for distributed storage
- Persistent storage management
- File system layout and organization optimized for performance
- Integration with DragonFly BSD's kernel architecture

### Design and Implementation
- Based on the original HAMMER file system design principles
- Enhanced with multi-device support for logical volume management
- Maintained under the 3-clause BSD License
- Developed as part of the DragonFly BSD open-source project

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  "@type": "Thing",
  "name": "HAMMER2",
  "description": "file system from DragonFly BSD",
  "sameAs": ["https://en.wikipedia.org/wiki/HAMMER2", "https://www.wikidata.org/wiki/Q6832090"],
  "additionalType": "file system",
  "operatingSystem": "DragonFly BSD",
  "license": "3-clause BSD License"
}

## References

1. [Source](http://bxr.su/d/sys/vfs/hammer2/)
2. [Source](https://www.phoronix.com/scan.php?page=news_item&px=HAMMER2-Multi-Volume)
3. [Source](http://bxr.su/d/sys/vfs/hammer2/hammer2.h)