Kybos: Self-Management for Distributed Brick-Based Storage

Current tools for storage system configuration management make offline decisions, recovering from, instead of preventing, performance specification violations. The consequences are severe in a large-scale system that requires complex actions to recover from failures, and can result in a temporary shutdown of the system. We introduce Kybos, a distributed storage system that makes online, autonomous responses to system changes. It runs on clusters of intelligent bricks, which provide local enforcement of global performance and reliability specifications and so isolate both recovery and application IO traffic. A management agent within Kybos translates simple, high-level specifications into brick-level enforcement targets, invoking centralized algorithms only when taking actions that require global state. Our initial implementation shows that this approach works well.