Deduplicating Devices Considered Harmful

Abstract

During the research for their interesting paper, "Reliably Erasing Data From Flash-based Solid State Drives," delivered at the FAST (File and Storage Technology) workshop at San Jose in February, Michael Wei and his co-authors from the University of California, San Diego discovered that at least one flash controller, the SandForce SF-1200, was by default doing block-level deduplication of data written to it. The SF-1200 is used in SSDs (solid-state disks) from, among others, Corsair, ADATA, and Mushkin.