设计实现了一个基于I/O(输入输出端口)的广域网数据异步复制系统(DARS),提出了一种基于“活动日志+位图”的数据复制方法,以较小的空间和时间开销,解决了生产中心掉电或网络阻塞造成的生产中心与灾备中心数据不一致问题.采用独立缓存代理,实现了数据缓冲服务的灵活部署,确保了低带宽复制链路下系统的I/O吞吐率.系统实现和测试表明:与基于日志卷的数据异步复制系统LogDARS相比,DARS以33%的日志存储空间开销,获得了20%的写性能提高. A DAS based on I / O (Input / Output Port) is designed and implemented, and a data replication method based on “Activity Log + Bitmap” is proposed to reduce the space and time overhead To solve the problem of data inconsistency between production center and disaster recovery center caused by power-down or network blockage in production center.Using independent cache agent, the data buffer service can be flexibly deployed to ensure system I / O throughput under low-bandwidth copy link The system implementation and testing show that DARS achieves 20% write performance improvement over Log Logs, a data-backed-up replication system based on Log Volumes, with 33% log storage overhead.