一种日志结构块存储系统一致性模型OA北大核心CSTPCD

With the increase of physical device capacity,the time and space complexity of log-structured block storage system consistency model and crash recovery are increasing.The scope of the consistent state is inversely propor-tional to the complexity of crash recovery and directly proportional to the probability of conflicts with user write re-quests.A single consistent timestamp(CST)is proposed to reduce the complexity of crash recovery.Then,the necessary and sufficient conditions and overhead of consistent state generation are analyzed;the write I/O state list(WSL)linked list is introduced to design a consistent state generation algorithm.Building on the consistency state generation algorithm,a multi write I/O mapping table(WMT),metadata management structure multi consist-ent state table(MCT)are proposed.As a result,conflicts between user requests and generation of consistent state are reduced to the access of linked list nodes.Based on the consistency model,a crash recovery algorithm is de-signed,and a log-structured block storage system single consistent state block device(SCB)is designed and implemented.Experimental results show that compared with allocate ondemand storage device(ASD),SCB's throughput is increased by 135.59％,and 99.90％tail latency is reduced by 42.89％,fileserver workload perform-ance is increased by 25.00％,crash recovery time is 1/23 of ASD.Compared with dm-thin,SCB's throughput is increased by 225.72％,and varmail workload performance is increased by 46.67％.