Currently, decentralized distributed storage system is widely used in various scenarios, because decentralized data placement algorithms observably improve scalability and robustness of distributed storage system. However, storage system applied with decentralized data placement algorithm suffers from uncontrollable data migration during expanding the clusters, which lead to dramatic fluctuation of performance. To maintain reliability and stability of storage system, administrators are under great pressure to migrate data during expansion or contraction. Not only the urgent time constraints to expansion but also low interference to foreground application are required during data migration period. It is a difficult challenge for in-experienced administrators to tackle.To address this challenge, this paper introduces Flimm, a fast and low-interference data migration manager that is aware of storage resource utilization and performs data migration with low interference to foreground applications. Flimm mitigates interference by scheduling a subset of migration tasks with careful consideration. Moreover, Flimm adapts to varying foreground application workloads through adaptive migration speed control, providing administrators with convenient and secure parameters for tuning. In our experiments, Flimm demonstrated a 1.2x acceleration in migration speed and achieved a 20% reduction in interference.
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