On The Storage Management And Data Recovery Of Solid State Disks

Traditional mechanical hard drives due to the limitation of its mechanical structure can not meet the high literacy rate, high adaptability requirements in certain areas. The invention of Solid State Drives(SSDs) gives a perfect solution to these problems. With the expansion of the application range of SSDs, the performance requirements for SSDs have become more and more demanding and the optimization of SSDs is the main problem to be solved.Solid state disk’s storage medium is a kind of NAND flash, due to limitations of the manufacturing process, it is inevitable to find bad blocks. Furthermore, the flash media is is very intolerant to erase. In order to play the advantages of flash memory, we must solve these limiting factors. Therefore people invent the loss balance mechanism and bad block management mechanism in the storage management system designed for the flash memory. Considering these issues, the solid state hard disk data recovery can not follow the mechanical hard drive and will be altered accordingly. To solve these problems, we do the following work in this paper:Firstly, the paper introduces storing principle of the flash memory medium and the concept of the flash translation layer(FTL). Based on these, a variety of algorithms for flash memory conversion layer including address mapping, loss of balance, garbage collection, bad block management, broken protection and so on are discussed, The mechanism of address mapping, the index of loss equalization algorithm and the optimization method and the process of garbage collection strategy are mainly studied. At the same time, the paper analyzes the common YAFFS2 file system on NAND flash memory.Secondly, the principle of data recovery based on YAFFS2 file system is studied on the basis of solid state hard disk storage management algorithm. We find a way to finish the file location and file assembly by using the object header file information, then try to reconstruct the historical evolution of the document by using the object header information.In the end, we study the test platform of SSDs, test the wear leveling algorithm of SSDs and explore the optimization of the wear leveling algorithm the realization of the file recovery technology under the Linux system. At the same time, based on the results of this paper, we analysis the future research direction of solid state hard disk in this paper.