Data Backup System Base On Dynamic Length Blocking Imcremental Backup Algorithm

In modern society, information system has long been an important part of production and daily life, and data in information systems is their blood, if the data in banks’, government agencies’information system is destroyed, the consequences will be unimaginable. The vulnerability of data in information systems makes it even worse. Data backup is the ultimate mean to deal with as the data is destroyed. Complete backup and rapid recovery of data can reduce the loss suffered from data breaches to a minimum.When evaluate a data backup system, the key factors includes time efficiency, space efficiency and reliability. Incremental backup is a backup strategy for the purpose of improving the space efficiency. It backs up only the differences between the previous version and current data, thus reducing the pressure of the storage and network bandwidth. Most existing incremental backup algorithm origins form Rsync algorithm. But the algorithm focuses on the text file backup while other types of files are not targeted. What is more, it did not give data privacy solution, data is expressly backed up. Obviously, to build an integrated time efficiency, space efficiency and reliability in one of the commercial data backup system, Rsync is not enough.The data backup system this paper designed is based on incremental backup of the file system, including incremental backup module, data encryption and decryption module, authentication module, file monitoring module and web management module. The main research focuses on the improvement of incremental backup algorithm, data security and system manageability.First of all, in incremental backup module we designed incremental backup algorithm for dynamic length of the block, whose key strategies include multi-level incremental backup and dynamic sub-block. The use of multi-level incremental backup avoids the transfer and storage of files with the same content, reducing duplication of data transfer and storage. The use of dynamic sub-block optimize the traditional file blocking, reducing the overhead of running time in blocking and the amount of data block fingerprint.Also in the data encryption and decryption module, incremental file encryption algorithm was designed. We chunk the file by Content Defined Chunking algorithm and encrypt chunks one by one, so that cipher text inherits the increment of plain text. Incremental backup can also be implemented when file was encryption. As a result, confidentiality of backup data is guaranteed.Finally, based on the above technical innovation, combined with identity authentication, file monitoring, web management module, we developed a set of practical data backup system. After coding, we tested it in LAN and use it in practice. Compared to the existing data backup systems, it has the advantage of convenient administration, high deduplication rate, strong data confidentiality, customizable backup strategy.