Design Of High-Performance Storage Device Based On NAND FLASH

With the fast development of computer servers and user requirement,the gap between I/O performance of storage systems and CPU performance is increasing.Due to frequent I/O requests,the I/O bottleneck of storage systems leads to the limitation of the overall system performance.How to effectively improve the I/O performance of storage systems has become an urgent problem.In recent years,the rapid development of solid-state storage devices based on NAND FLASH has made it possible to solve this problem.However,due to the semiconductor characteristics of NAND FLASH,there're some problems in the durability and reliability of the storage device while achieving high read/write performance.This thesis designs a high read/write performance,high durability and high reliability storage device based on NAND FLASH,using the technology of simulating Trinary-level cell(TLC)as a Single-level cell(SLC)to directly cover effective data on the pages for three times before the SLC cache is wiped,to improve the read/write performance of a single solid-state disk(SSD);based on this,the use of a PCIe switch to achieve a PCIe 3.0 x16 interface high-performance hard disk controller card with four SSDs,with soft-RAID to further enhance the storage device's overall read/write performance;at the same time,the system uses a method by recovering TLC bad block to the SLC mode and writing the ECC stream and the variable user data into the SLC cache in the RAID data redundancy mode to optimlize the overall durability of the storage device;finally,the controller card has appropriate solid-state capacitors on the board to implement the power failure data protection function under the notification mechanism for power loss and power recovery,thus,in the case of sudden power failure,the data of four SSDs on the controller card can be guaranteed as the SSDs can complete updating the mapping table and writing back the cache buffer data to the NAND FLASH,which improve t the reliability of the storage device.The design has a certain meaning on meeting the needs of individuals and enterprises for high-performance storage,and application scenarios in the fields of video file processing,video streaming server,database processing and cloud computing storage,etc.