While the NAND flash based solid state drive (SSD) has been widely adopted by both custom electronics and enterprise storages, the isolation of the file system and the information of the real status of the physical storage space will inevitably degrade the overall efficiency as well as the reliability of the storage and could become the bottleneck of the high-performance test systems. Open Channel Solid State Drive (OCSSD) has been proposed to resolve this dilemma by exposing details of the physical storage state to the host system.

Base on the OCSSD architecture, this paper presents Strictly Sequential Writing (SSW), a highly efficient strictly sequential writing method to further reduce the garbage collection operations of SSD and ultimately prolong its lifetime and meanwhile improve the I/O performance of the storage system. The basic idea is to avoid any unwanted interruptions of random read/write operations for sequential write operations by exploiting the metadata of the file system. Thus, we can reduce the number of garbage collection operations a lot by properly allocating these unbroken sequential write operations. Then the reliability of the storage system will be greatly enhanced. We propose two strategies to optimize the identification and the reallocation of sequential write operations. The experimental results show that SSW can reduce the number of garbage collection operations on average 26.65% compared with the baseline scheme.

尽管基于NAND闪存的固态驱动器（SSD）已被定制电子产品和企业存储广泛采用，但是文件系统的隔离以及物理存储空间的真实状态信息将不可避免地降低整体效率以及存储的可靠性，并可能成为高性能测试系统的瓶颈。已经提出了开放通道固态驱动器（OCSSD）通过向主机系统公开物理存储状态的详细信息来解决这一难题。

本文基于OCSSD架构，提出了严格顺序写入（SSW），这是一种高效的严格顺序写入方法，可进一步减少SSD的垃圾回收操作并最终延长其使用寿命，同时提高存储系统的I / O性能。基本思想是通过利用文件系统的元数据来避免对顺序写入操作的随机读取/写入操作的任何不必要的中断。因此，通过适当地分配这些连续的连续写操作，我们可以大大减少垃圾回收操作的数量。这样可以大大提高存储系统的可靠性。我们提出了两种策略来优化顺序写操作的标识和重新分配。