The write constraints of Multi-Level Cell (MLC) NAND flash memory make most of the existing flash translation layer (FTL) schemes inefficient or inapplicable. In this article, we solve several fundamental problems in the design of MLC flash translation layer. The objective is to reduce the garbage collection overhead to reduce the average system response time. We make the key observation that the valid pages copy is the essential garbage collection overhead. Based on this observation, we propose two approaches, namely, concentrated mapping and postponed reclamation, to effectively reduce the valid pages copy. Besides, we propose a progressive garbage collection that can well utilize the system idle time to reclaim more spaces. We conduct a series of experiments on an embedded developing board with a set of benchmarks. The experimental results show that our scheme can achieve a significant reduction in the average system response time compared with the previous work.

中文翻译：

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MNFTL

Multi-Level Cell (MLC) NAND闪存的写入限制使得大多数现有的闪存转换层(FTL)方案效率低下或不适用。在本文中，我们解决了 MLC 闪存转换层设计中的几个基本问​​题。目的是减少垃圾收集开销以减少平均系统响应时间。我们主要观察到有效页面副本是基本的垃圾收集开销。基于这一观察，我们提出了两种方法，即集中映射和延迟回收，以有效减少有效页面副本。此外，我们提出了一种渐进式垃圾收集，可以很好地利用系统空闲时间来回收更多空间。我们在具有一组基准的嵌入式开发板上进行了一系列实验。