The Charles

Weld Boathouse on the Glorious Charles.
Weld Boathouse on the Glorious Charles.


The Charles is a file system for high-performance parallel I/O on large and heterogeneous parallel computers. The design is built within two ideals:

  • no locking or synchronization.
  • only hints are global. All other state is local and decentralized.

These ideals improve scheduling flexibility, facilitating higher throughput under system change and instability.

Hints free up the design of the metadata server. It can range in architecture from a single server to a peer-to-peer network. Michael Tucker's undergraduate thesis compared the simulated performance of a hybrid organization against the extreme points of a centralized server and a pure decentralized peer-to-peer system based on MIT Chord.

Please contact Lex for source code.


    • Michael J. Tucker, "Central Organization for a Peer-centric System"Undergraduate Thesis, Harvard University, Cambridge, MA, USA, June 2003.
    • Lex Stein, Michael J. Tucker, and Margo I. Seltzer "Building a Reliable Mutable File System on Peer-to-peer Storage"International Workshop on Reliable Peer-to-peer Distributed Systems, Osaka, Japan, October 2002.  ]
    • Lex Stein, MIchael J. Tucker, and Margo I. Seltzer "> Harvard CS Technical Report HU-TR-04-02, Cambridge, MA, May 2002.



Margo Seltzer
Lex Stein 
Michael Tucker