固态存储系统PCIe接口的设计方法与实现
发布时间：2018-09-05 14:24
【摘要】：随着信息技术的快速发展，存储器的性能逐渐成为了研究热点。传统磁盘由于其机械装置的限制，在性能、能耗上越来越不能满足一些高性能的应用需求。基于NANDFlash（闪存）的固态盘具有低能耗、非易失、高随机读写性能等很良好的特性，正逐步取代磁盘成为主流的存储介质。 常用的固态盘接口有USB、SATA等，这些接口由于其物理特性，在一定程度上限制了固态盘的读写速度，成为了固态盘的性能瓶颈。因此，目前高性能固态盘接口的研究转向了PCIe存储接口，其全双工、多请求处理能力以及无序处理能力给存储性能带来极大的提升，而且可扩展的接口带宽大大提升了链路速度。因此PCIe在很多有高性能存储需求的场合已经得到了广泛的应用。 NVMe(Non-Volatile Memory express)是PCIe固态存储器的通用逻辑层协议，规定了主机和固态盘之间的通信方式。论文研究了如何通过NVMe协议构造一个PCIe固态存储系统，使主机端软件和设备端固态存储子系统进行通信。其中包括在Linux系统中编写驱动程序使系统能够识别出PCIe固态盘，，并作为一个普通的磁盘使用。在实现方式上，主机端和固态盘控制器端通过信息队列来传递读写命令，并采用DMA(Direct Memory Access)方式传输数据。除此之外，论文提出了一种固态盘性能优化的算法，主要的功能是分析主机端上层软件对固态盘的I/O请求，提取读写请求的读写频率等特征，并利用NVMe协议中优化的寄存器接口和指令集等高级特性，根据主机端统计的固态盘中逻辑块的读写请求特征信息对缓存中的替换策略进行相应的改进，将读写频率高的逻辑块换入缓存，而将读写频率低的逻辑块换出缓存，从而提升缓存的命中率。实验结果表明，该算法提高了缓存的命中率，降低了数据写回NAND FLASH的次数，增加了固态盘的寿命。
[Abstract]:With the rapid development of information technology, memory performance has gradually become a research hotspot. Due to the limitation of mechanical devices, traditional disks can not meet the requirements of high performance applications in terms of performance and energy consumption. The solid-state disk based on NANDFlash (flash memory) has the advantages of low energy consumption, non-volatile, high random reading and writing performance, and is gradually replacing the disk as the mainstream storage medium. The commonly used solid-state disk interfaces include USB,SATA and so on. Due to their physical properties, these interfaces restrict the read and write speed of the solid-state disk to a certain extent and become the bottleneck of the performance of the solid-state disk. Therefore, the current research on high performance solid-state disk interface has shifted to PCIe storage interface. Its full-duplex, multi-request processing capability and disordered processing capability have greatly improved the storage performance. Moreover, the extensible interface bandwidth greatly improves the link speed. Therefore, PCIe has been widely used in many applications with high performance storage requirements. NVMe (Non-Volatile Memory express) is a universal logic layer protocol for PCIe solid-state memory, which specifies the mode of communication between host and solid-state disk. In this paper, we study how to construct a PCIe solid-state storage system through NVMe protocol, so that the host side software can communicate with the device side solid-state storage subsystem. This includes writing a driver in a Linux system to enable the system to recognize PCIe solid-state disks and use them as an ordinary disk. In the implementation, the host side and the solid state disk controller terminal pass the read and write command through the information queue, and transmit the data by DMA (Direct Memory Access) mode. In addition, this paper proposes an algorithm to optimize the performance of solid-state disk. The main function of this algorithm is to analyze the I / O request of the upper layer software of the host, and to extract the read / write frequency of the read / write request. Using the advanced features such as register interface and instruction set which are optimized in NVMe protocol, the replacement strategy in cache is improved according to the read and write request feature information of logic block in solid state disk which is counted by the host side. The logical block with high read and write frequency is replaced in the cache, and the logic block with low read and write frequency is swapped out of the cache to improve the hit rate of the cache. Experimental results show that the algorithm improves the hit ratio of cache, reduces the number of data written back to NAND FLASH, and increases the lifetime of solid state disk.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TP333
本文编号：2224553
[Abstract]:With the rapid development of information technology, memory performance has gradually become a research hotspot. Due to the limitation of mechanical devices, traditional disks can not meet the requirements of high performance applications in terms of performance and energy consumption. The solid-state disk based on NANDFlash (flash memory) has the advantages of low energy consumption, non-volatile, high random reading and writing performance, and is gradually replacing the disk as the mainstream storage medium. The commonly used solid-state disk interfaces include USB,SATA and so on. Due to their physical properties, these interfaces restrict the read and write speed of the solid-state disk to a certain extent and become the bottleneck of the performance of the solid-state disk. Therefore, the current research on high performance solid-state disk interface has shifted to PCIe storage interface. Its full-duplex, multi-request processing capability and disordered processing capability have greatly improved the storage performance. Moreover, the extensible interface bandwidth greatly improves the link speed. Therefore, PCIe has been widely used in many applications with high performance storage requirements. NVMe (Non-Volatile Memory express) is a universal logic layer protocol for PCIe solid-state memory, which specifies the mode of communication between host and solid-state disk. In this paper, we study how to construct a PCIe solid-state storage system through NVMe protocol, so that the host side software can communicate with the device side solid-state storage subsystem. This includes writing a driver in a Linux system to enable the system to recognize PCIe solid-state disks and use them as an ordinary disk. In the implementation, the host side and the solid state disk controller terminal pass the read and write command through the information queue, and transmit the data by DMA (Direct Memory Access) mode. In addition, this paper proposes an algorithm to optimize the performance of solid-state disk. The main function of this algorithm is to analyze the I / O request of the upper layer software of the host, and to extract the read / write frequency of the read / write request. Using the advanced features such as register interface and instruction set which are optimized in NVMe protocol, the replacement strategy in cache is improved according to the read and write request feature information of logic block in solid state disk which is counted by the host side. The logical block with high read and write frequency is replaced in the cache, and the logic block with low read and write frequency is swapped out of the cache to improve the hit rate of the cache. Experimental results show that the algorithm improves the hit ratio of cache, reduces the number of data written back to NAND FLASH, and increases the lifetime of solid state disk.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TP333
【参考文献】
相关期刊论文 前2条
1 韩勇豪;王少云;;一种NAND Flash动态坏块管理算法的设计与实现[J];信息化研究;2011年03期
2 黄滨;俞建新;;大容量闪存的层次型热数据识别框架[J];计算机工程;2008年22期
本文编号：2224553
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