Causality-Based Versioning

Versioning file systems provide the ability to recover from a variety of failures, including file corruption, virus and worm infestations, and user mistakes. However, using versions to recover from data-corrupting events requires a human to determine precisely which files and versions to restore. We can create more meaningful versions and enhance the value of those versions by capturing the causal connections among files, facilitating selection and recovery of precisely the right versions after data corrupting events. We determine when to create new versions of files automatically using the causal relationships among files. The literature on versioning file systems usually examines two extremes of possible version-creation algorithms: open-to-close versioning and versioning on every write. We evaluate causal versions of these two algorithms and introduce two additional causality-based algorithms: Cycle-Avoidance and Graph-Finesse. We show that capturing and maintaining causal relation...

• Type: Journal
• Year: 2009
• Where: FAST
• Authors: Kiran-Kumar Muniswamy-Reddy, David A. Holland
• Keywords: Causal, FAST 2009, Meaningful Versions, Operating System, Versioning