Unionfs: A Stackable Unification File System (original) (raw)

Unionfs logo 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 FiSTproject which includes the Wrapfs wrapper stackable file system.

Software Download:

Unionfs releases of kernel code and user-level utilities, as well as snapshots, are available via FTPorHTTP. Full kernel versions patched with Unionfs can be accessed via Git fromour 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 Gitrepository. Here are instructions how to check out the latest code with Git.

See list of mirror sites.

Kernel Version Compatibility:

Mailing Lists:

Click on the list name below to access the subscription Web page. That page will also tell you how to post to the list, access the lists' archives, change your subscription status, etc.

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

Miscellaneous:

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.

Various articles and tutorials involving Unionfs:

Projects Using 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

Journal Articles:

# 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

Conference and Workshop Papers:

# 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

Technical Reports:

# 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

Past Students:

# 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)

Sponsors:

# 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