Research And Implementation Of The Way Of Metadata Access In The Network Backup System

With the rapid growth of information, the importance of information is increasing, the completeness and security of data —— the correlative objectives of information become the most important things of the whole system. The backup technology is one of the most important methods to maintain the security and availability of the system. Based on network storage, a network backup system can be built to satisfy the needs of applications and performance.Network storage that band together storage and network is being developed rapidly. USN (Unified Storage Network) based on storage over IP is merged by SAN and NAS through the management of storage virtualization. It can optimize the storage system by reducing the expense of management and sharing the storage data. By analyzing the principle and structure of the network backup system, some important techniques of network backup are thoroughly researched.Network backup is the concrete application of a network storage system. A network backup system based on TCP/IP is successfully implemented. It includes three parts: Backup Server Management Software on Windows server, Client and Backup Source Proxy Software on data source, Backup Destination Proxy Software on storage resource. From these aspects, the way of metadata's management is designed. Finally the kernel data structures, database and interface functions are designed in detail.In order to improve the performance of the network backup system, a hash function computes the fingerprint which is a unique hash of a data block's or a file's contents. To realize Snapshot, some fingerprints construct a tree structure storing a linear sequence of blocks. The approach can avoid the tradeoff between the performances of backup and restore operations, and it can also provide compress backup, increase data security and maintain data consistency.From the experiments in 100M Ethernet environment, it is concluded that the speed of this network backup system is higher than that of FTP in our test environment.