A Fan-Out Snapshotting File System

Snapshots allow users to modify the file system, while maintaining the ability to view the file system precisely as it was when a snapshot was taken. Snapshots are useful because they provide versioning, and allow consistent access to an entire tree (e.g., so that backups can be taken on a live system).

We will build a fan-out stackable snapshotting file system that supports an arbitrarily large number of snapshots, using Unionfs to provide the core fan-out infrastructure. When a snapshot is taken, an empty high priority branch will be inserted into the fan. Any modifications are made within the new branch, and the original data is preserved in the the previous branches.

There are three methods of accessing a snapshot. A user may use a separate name space (e.g., /snapshots/03132003 for March 13, 2003). A special operator may be used to access the previous snapshot (e.g., ... will go to the previous snapshot of that directory). Finally, We will update the VFS to allow one path to have multiple per-entity trees. The user can run a new utility set-snap that informs Snapshotfs which view the user or process is using.

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 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 Operating System Support for Extensible Secure File Systems PS PDF BibTeX Stony Brook U. CS TechReport FSL-04-02 May 2004 Ph.D. Research Proficiency Exam (RPE)

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)


# 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