Research On Lifetime Optimizationbased On All Flash Hard Disk Array

With the development of related technologies of Flash flash memory devices and the higher requirements for data storage performance in the era of big data,Solid State Drive(SSD)has a wide range of characteristics due to its small size,low power consumption,excellent performance,and good stability.It is widely used in personal mobile terminals,embedded devices,big data storage and other fields.In a large-scale data storage scenario,a RAID(Redundant Arrays of Independent Disks,independent redundant disk array)controller is generally used to combine multiple hard disks and apply to a storage system in the form of a hard disk array.In this study,in order to improve the reliability of flash memory arrays,a wear leveling function is designed and implemented.This research mainly includes the wear leveling program design and related strategy research of SSD arrays.The idea of variable stripe structure in the elastic stripe method is innovatively used to adjust the write request load of the array.Combined with the working characteristics of the array,a wear leveling method is realized.Balance method.And design stripe selection strategy and trigger strategy to improve the operating efficiency of wear leveling function,design load balance strategy to optimize the request load of the array,and reduce the impact of wear leveling process on the array performance.This paper is mainly divided into three parts: First,it introduces the related research of SSD,including the internal research of SSD and the research of storage system composed of SSD,and expounds the basic storage concepts such as RAID array,storage system,wear leveling and so on.The second is to analyze the read and write request characteristics of RAID5 arrays,explain the theoretical feasibility of the wear leveling function design,and realize the various functional modules of wear leveling through programming design.The third is to propose optimization strategies based on wear leveling procedures,including stripe selection strategy,trigger strategy,and load balancing strategy.The test results show that,compared with the traditional RAID5 array,the wear leveling function gradually reduces the standard deviation of the total write volume of each hard disk in the array,and the array develops to a wear leveling state,which achieves the optimization of the life consumption process of SSDs in the all-flash hard disk array.The goal is to improve the reliability of the array.And the results show that the load balancing optimization strategy can improve the read and write performance by about 57% when the array is in wear leveling state.