DATE: Thursday , March 20, 2003
     TIME: Noon - 1 pm 
     PLACE: Hamerschlag Hall D-210
 SPEAKER: 
    Craig Soules 
     Carnegie Mellon University 
TITLE: 
    Metadata Efficiency in Versioning File Systems 
ABSTRACT: 
    Versioning file systems retain earlier versions of modified files, allowing 
    recovery from user mistakes or system corruption. Unfortunately, conventional 
    versioning systems do not efficiently record large numbers of versions. 
    In particular, versioned metadata can consume as much space as versioned 
    data. This talk examines two space-efficient metadata structures for versioning 
    file systems and describes their integration into the Comprehensive Versioning 
    File System (CVFS), which keeps all versions of all files. Experiments 
    with CVFS verify that its current version performance is similar to that 
    of non-versioning file systems while reducing overall space needed for 
    history data by a factor of two. Although access to historical versions 
    is slower than conventional versioning systems, checkpointing is shown 
    to mitigate and bound this effect. 
BIO:
    Craig Soules is a 3rd year graduate student in Computer Science who has 
    been working on versioning file systems off and on for over 2 years. He 
    hopes that after the completion of this talk he will be able to leave 
    all that in the past and work on completing a thesis proposal. This talk 
    is both a practice talk for an upcoming FAST presentation and (hopefully) 
    fulfillment of his speaking requirement. 
SDI / LCS Seminar Questions?
    Karen Lindenfelser, 86716, or visit www.pdl.cmu.edu/SDI/ 
