This project builds a stackable unification file system, which can appear to merge the contents of several directories (branches), while keeping their physical content separate. Unionfs is useful for unified source tree management, merged contents of split CD-ROM, merged separate software package directories, data grids, and more. Unionfs allows any mix of read-only and read-write branches, as well as insertion and deletion of branches anywhere in the fan-out. To maintain unix semantics, Unionfs handles elimination of duplicates, partial-error conditions, and more. Unionfs is part of the larger FiST project which includes the Wrapfs wrapper stackable file system. |
Unionfs releases of kernel code and user-level utilities, as well as snapshots, are available via FTP or HTTP. Full kernel versions patched with Unionfs can be accessed via Git from our git server.
Download Unionfs 2.x with experimental On Disk Format (ODF) support. Read the ODF Design Document.
Unionfs 2.x is maintained in a Git repository. Here are instructions how to check out the latest code with Git.
See list of mirror sites.
List Name | Purpose | Who Can Subscribe | Who Can Post | Comments |
unionfs | For users' and developers' questions, announcements, bug reports, and general. | Anyone | Subscribers only | |
unionfs-cvs | For CVS commit logs | Anyone | No one: automated CVS logs only |
If you find a problem, please describe it in detail and submit a bug report via Bugzilla.
Some Unionfs users congregate in #unionfs on the FreeNode IRC network.
Users of Real Time (RT) Linux can find additional RT patches for Unionfs.
No. | Name | Description |
1 | ALT Linux | ALT Linux distribution build kit, that allow you to preparing customized distribution or LiveCD, based on ALT Linux Sisyphus packages repository |
2 | Archie | Arch Live Project |
3 | Ark Linux Live | Ark Linux Live is a "Live CD" version of Ark Linux. |
4 | Blutopia | Cluster Life-cycle Management, IBM Research Austin |
5 | ClefAgreg | ClefAgreg, a bootable USB key dedidaced to Mathematics, using Debian GNU/linux |
6 | Clusterix | Clusterix is a modular Linux live CD based on Morphix, Knoppix and Debian GNU/Linux. |
7 | Danix | Czech Knoppix-like distribution |
8 | Debian Linux | The Debian Linux distribution |
9 | DSS-Live | A system development environment to create Debian-based live Linux systems. |
10 | Elive | A Debian-based LiveCD centered around the Enlightenment window manager. |
11 | Foresight Linux | Foresight Linux is a Distribution which showcases the latest and greatest version of the GNOME Desktop Environment and Freedesktop.org |
12 | GeLuX | Swiss French Linux distribution based on Morphix |
13 | Generations Linux | Boot/LiveCD containing GNU/Linux and KDE |
14 | Gentoo Linux | The Gentoo Linux distribution |
15 | Gibraltar firewall | Gibraltar Security Firewall LiveCD |
16 | Gnome Live | A Gnome LiveCD |
17 | GoblinX | GoblinX is a live CD based on Slackware, with standardized themes for novice users. |
18 | grml | LiveCD for system administrators and texttool-users |
19 | INSERT | A Linux rescue system with NTFS write support and virus scanning that fits on a credit-card size CD. |
20 | Kanotix | Knoppix-based LiveCD. |
21 | Knoppix | Bootable CD with a collection of GNU/Linux Software |
22 | LiveBackup | A Framework to create bootable live-ISO's from installed Linux systems |
23 | m-dist | Audio/MIDI LiveCD based on Slackware. |
24 | Mandriva Linux | The Mandriva Linux distribution |
25 | Mandriva One | Live & Install CD with everything for office work, Internet and multimedia. |
26 | MiniMyth | A network-boot distribution that runs the MythTV PVR software. |
27 | Morphix | Modular Knoppix-based LiveCD |
28 | NOPPENLINUX | SUSE Linux based LiveCD |
29 | open Networking Routers | a set of network appliances based on open-source |
30 | open Thin Client | A comprehensive management solution and operating system for thin clients |
31 | OpenSuSE Linux 10.2 | The Open-SuSE Linux distribution |
32 | PaiPix | A remastered Knoppix with a focus on Scientific applications. |
33 | rBuilder Online | An online tool for creating and maintaining tailored Linux distributions including LiveCDs, Installable CDs, VMWare Images, QEMU Images, and other image types from custom package sets. |
34 | redWall Firewall | A bootable CD-ROM Firewall. |
35 | Scientific Linux Live System | LiveCD and LiveDVD of Scientific Linux |
36 | T2 | A "Distribution Build Kit" that allows you to select various targets for a customized distribution (e.g., router, desktop, or LiveCD). |
37 | Taprobane | A Debian-based LiveCD that is customized for convenience without "dumbing down" the user's experience. |
38 | Tugux | Portuguese Linux Distribution |
39 | Ubuntu Linux (Gutsy/Edgy) | The Ubuntu Linux distribution |
40 | Xarnoppix | A Catalan-localized LiveCD focused on education |
# | Title (click for html version) | Formats | Published In | Date | Comments |
1 | On Incremental File System Development | PS PDF BibTeX | ACM Transactions on Storage (TOS) | May 2006 | |
2 | Versatility and Unix Semantics in Namespace Unification | PS PDF BibTeX | ACM Transactions on Storage (TOS) | Feb 2006 | |
3 | Unionfs: Bringing File Systems Together | BibTeX | Linux Journal | Dec 2004 |
# | Title (click for html version) | Formats | Published In | Date | Comments |
1 | Kernel Support for Stackable File Systems | PS PDF BibTeX | 2007 Ottawa Linux Symposium | Jun 2007 | |
2 | Making Linux Stacking-Friendly | BibTeX | First Linux Storage and Filesystem Workshop, held in conjuction with the fifth USENIX Conference on File and Storage Technologies (FAST 2007) | Feb 2007 | |
3 | UnionFS: User- and Community-oriented Development of a Unification Filesystem | PS PDF BibTeX | 2006 Ottawa Linux Symposium | Jul 2006 |
# | Title (click for html version) | Formats | Published In | Date | Comments |
1 | Versatility and Unix Semantics in a Fan-Out Unification File System | PS PDF BibTeX | Stony Brook U. CS TechReport FSL-04-01b | Oct 2004 |
# | Name (click for home page) | Program | Period | Current Location |
1 | Charles P. Wright | PhD | May 2003 - May 2006 | Partner, Senior Software Architect, Illumon (New York, NY) |
2 | Shrikar Archak | MS | Sep 2009 - Dec 2010 | Senior Software Engineer, Core Deduplication Filesystem group, Datadomain/EMC |
3 | Jay Pradip Dave | MS | May 2003 - Dec 2003 | Head of Product Management, Enterprise platform and Administrative experience, Qualtrics Qualtrics (Seattle, WA) |
4 | Puja Gupta | MS | Jan 2003 - Dec 2003 | Software Engineering Manager, Darwin Runtime, Core OS, Apple Inc. (Cupertino, CA) |
5 | Rachita Kothiyal | MS | Sep 2007 - May 2009 | Member of Technical Staff, Network Appliance, Inc. (Sunnyvale, CA) |
6 | Arun Krishnakumar | MS | Jan 2005 - Dec 2005 | Computer Scientist, Acrobat team, Adobe Systems (India) |
7 | Harikesavan Pathangi Krishnan | MS | Jan 2003 - Dec 2003 | Software Engineer, Engineering department for WAFS product line, Packeteer, Inc. (South Plainfield, NJ) |
8 | Li Mengyang | MS | May 2014 - Dec 2014 | Member of Technical Staff, Foundation Group, Nutanix (San Jose, CA) |
9 | Dongju Ok | MS | Sep 2014 - May 2016 | Software Engineer, Application Team, Commvault Systems Inc. (Tinton Falls, NJ) |
10 | David Quigley | MS | Sep 2005 - May 2007 | ZFS Linux Software Engineer, High Performance Data Division Intel (Longmont, CO) |
11 | Mohammad Nayyer Zubair | MS | Jan 2004 - Dec 2004 | Software Developer, Bloomberg (New York, NY) |
12 | Yiannis Pericleous | BS/MS | Sep 2006 - Jun 2007 | Software Developer, Albourne Partners (Nicosia, Cyprus) |
13 | David Quigley | BS | Dec 2004 - Aug 2005 | ZFS Linux Software Engineer, High Performance Data Division Intel (Longmont, CO) |
14 | Josef "Jeff" Sipek | BS | Jul 2005 - May 2008 | Senior Member of Technical Staff, Nutanix (Boston, MA) |
15 | Mohammad Nayyer Zubair | BS | May 2003 - Dec 2003 | Software Developer, Bloomberg (New York, NY) |
# | Sponsor | Amount | Period | Type | Title (click for award abstract) |
1 | NSF Trusted Computing (TC) | $400,000 | 2003-2006 | Sole PI | A Layered Approach to Securing Network File Systems |