A Hybrid Flash Translation Layer with Adaptive Merge for SSDs

Abstract

The Flash Translation Layer (FTL) in Solid-State Disks (SSDs) maps logical addresses to physical addresses for disk drive virtualization. In order to reduce garbage collection overhead, we propose full associative striped block-level mapping. In addition, an adaptive merge is proposed to avoid excessive data block reconstructions during garbage collection. With these mechanisms, the write latency is improved up to 78% in comparison with the previous multichannel hybrid FTLs in a sample PC trace. The performance improvements stem from 52% reduced garbage collection.