, March 20, 2003
Noon - 1 pm
Hamerschlag Hall D-210
Carnegie Mellon University
Metadata Efficiency in Versioning File Systems
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.
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.