The performance of file systems and related software depends on characteristics of the underlying file-system image (i.e., file-system metadata and file contents). Unfortunately, rather than benchmarking with realistic filesystem images, most system designers and evaluators rely on ad hoc assumptions and (often inaccurate) rules of thumb. Furthermore, the lack of standardization and reproducibility makes file system benchmarking ineffective. To remedy these problems, we develop Impressions, a framework to generate statistically accurate file-system images with realistic metadata and content. Impressions is flexible, supporting user-specified constraints on various file-system parameters using a number of statistical techniques to generate consistent images. In this paper we present the design, implementation and evaluation of Impressions, and demonstrate its utility using desktop search as a case study. We believe Impressions will prove to be useful for system developers and users ali...
Nitin Agrawal, Andrea C. Arpaci-Dusseau, Remzi H.