A Flexible Garbage Collection Scheme with Low Overhead for ZNS SSDs

Garbage collection (GC) has long impacted the ability of solid state disks (SSD) to function properly and has become an important issue that many memory manufacturers are eager to address. In recent years, with the advent of zoned namespace SSDs (ZNS SSD), the garbage collection process has become more controllable. The host side is able to selectively trigger the process of garbage collection and the area to be covered, so as to meet the real-time demand of applications. In this paper, we propose a flexible garbage collection scheme that aims to avoid affecting the normal read and write operations of applications as much as possible and further reduce the overhead of garbage collection. The experiments are conducted in a simulator capable of emulating zoned storage. Extensive experiments show that our approach is able to reduce read and write latency while reducing write amplification.