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The ADvanced Systems Laboratory (ADSL)
Publication abstract

SQCK: A Declarative File System Checker

Haryadi S. Gunawi, Abhishek Rajimwale, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau
Department of Computer Sciences, University of Wisconsin-Madison


The lowly state of the art for file system checking and repair does not match what is needed to keep important data available for users. Current file system checkers, such as e2fsck, are complex pieces of imperfect code written in low-level languages. We introduce SQCK, a file system checker based on a declarative query language; declarative queries are a natural match for the cross-checking that must be performed across the many structures of a file system image. We show that SQCK is able to perform the same functionality as e2fsck with surprisingly elegant and compact queries. We also show that SQCK can easily perform more useful repairs than e2fsck by combining information available across the file system. Finally, our prototype implementation of SQCK achieves this improved functionality with comparable performance to e2fsck.

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