Block-Level Data Migration in Tiered Storage System

Managing data growth continues to be the biggest challenge for IT. And tiered storage, a solid way to Information Lifecycle Management (ILM), is very helpful to reduce the cost and improve the storage efficiency in data center. However, data migration is the primary challenge to implement tiered storage management, and it's hard to be resolved by traditional data migration solutions, which are mainly relying on experience of administrators and manual migration according to storage capacity usage and data access frequency. This paper proposes a novel bi-directional migration policy (migration with double thresholds based on feedback, MDTF), based on block-level data valuation and fully automation process. MDTF aims to achieve balance between storage QoS and migration costs by double thresholds, to narrow the migration scope of block-level data objects, and the analysis shows that MDTF is an efficient block-level data migration policy comparing with traditional migration policies.