Research And Implementation Of Continuous Data Protection System Based On ISCSI

With the widespread use of computer in social life, the data become a great treasure for people. Hardware failure and soft errors which were caused by human are two major threats to data security. RAID use a controller to calculate disk data parities automatically, if one disk fails, RAID can use these parities to recover data. It can only cover the hardware failure threat. Although backup can deal with soft errors, we can not avoid data loss since backup always be done in period. CDP is a new technique for data protection. It is mainly used to cover the soft errors, and it can make sure there is no data loss. CDP can be implemented either by hardware or software. In this paper, we do some research on software implementation for CDP. We point out the key techniques during the implementation and at the end analyze the performance in details.The research work and contribution in this paper are:Make the applications and functions of CDP clear. CDP is a supplement to the traditional backup technique. It solves problems in backup technique that it would take a long time to restore the data and there still have some data loss.Design and implement the disk storage based on Log-Struct infrastructure, and analyze the performance in details.The design of data read hierarchy. We divide the read process into several levels. Different levels differ from their read performance. We achieve a high performance for the whole system through a high hit rate in the upper levels of read.Analyze the space occupation, read and write performance of CDP, the result gives a support to performance analysis in theory.