Efficient management for large-scale flash-memory storage systems with resource conservation

Many existing approaches on flash-memory management are based on RAM-resident tables in which one single granularity size is used for both address translation and space management. As high-capacity flash memory is becoming more affordable than ever, the dilemma of how to manage the RAM space or how to improve the access performance is emerging for many vendors. In this article, we propose a tree-based management scheme which adopts multiple granularities in flash-memory management. Our objective is to not only reduce the run-time RAM footprint but also manage the write workload, due to housekeeping. The proposed method was evaluated under realistic workloads, where significant advantages over existing approaches were observed, in terms of the RAM space, access performance, and flash-memory lifetime.