The case for active block layer extensions

Abstract

Self-managing storage systems have recently received attention from the research community due to their promised ability of continuously adapting to best reflect high-level system goal specifications. However, this eventuality is currently being met by both conceptual and practical challenges that threaten to slow down the pace of innovation. We argue that two fundamental directions will help evolve the state of self-managing storage systems: (i) a standardized development environment for self-management extensions that also addresses ease of deployment, and (ii) a theoretical framework for reasoning about behavioral properties of individual and collective self-management extensions. We propose Active Block Layer Extensions (ABLE), an operating system infrastructure that aids the development and manages the deployed instances of self-management extensions within the storage stack. ABLE develops a theory behind block layer extensions that helps address key questions about overall storage stack behavior, data consistency, and reliability. We exemplify specific storage self-management solutions that can be built as stackable extensions using ABLE. Our initial experience with ABLE and few block layer extensions that we have been building, leads to believe that the ABLE infrastructure can substantially simplify the development and deployment of robust, self-managing, storage systems.