The Research On Single Disk Failure Recovery Based On Erasure Codes

In modern storage systems,the rapid growth of data size has led to the widespread use of large-capacity data disks.However,due to the appearance of various disk failures,devices with large data disks in turn increase the likelihood of data loss or damage.In order to deal with disk failures and ensure data integrity,researchers have proposed many methods.One of the most widely used types is to use redundant methods to restore lost data by storing a small amount of redundant information in advance.An important implementation of this type of approach is erasure code,an important feature of this code is that the solution can tolerant some disk failures.As the most common case for all recovery mechanisms,single disk failure recovery has received more attention in the past few years.However,most of the existing coding schemes are focused on stripe-level recovery and rarely consider improving the performance of single disk failure recovery.In response to this situation,this paper propose an efficient erasure coding scheme called L-code encoding,which can tolerate double disk failures.Through the different layout and calculation of redundant elements,this scheme can improve the performance of single disk failure recovery.The main research content of this paper is stated as follows.(1)This paper proposed an efficient erasure coding scheme named L-code.Like most traditional schemes,L-code has the ability to tolerate double disk failures,but in terms of data encoding and single disk failure recovery,the performance of L-code is better.(2)This paper present and prove the lower limit of disk reads used to recover a single disk failure in L-code scheme and present the corresponding recovery scheme.(3)This paper performed experiments on L-code scheme and compared it with other coding schemes.The results show that L-code is 20.9% higher than the optimized EVENODD,13.64% for the optimized RDP,31.6% for the optimized Liberation and 13.76% for the optimized H-code in terms of single disk failure recovery performance.And in coding complexity aspect,L-code is 40.14% higher than the optimized EVENODD,9.74% for the optimized Liberation and 1.06% for the optimized H-code,but 1.12% slower than the optimized RDP.