Data Access,Sharing And Control In Wide-area Storage Virtualization System

Wide-area storage virtualization is the extending of the local-area storage virtualization technology. It is responsible to manage distributed data in the different autonomous domains on WAN, realize data sharing between users and provide users a storage service of high efficiency, high reliability, and high expandability. The paper has analyzed current research status of related systems in domestic and foreign. Base on this and according to the distributed characteristic of storage resource as well as the characteristic of how users use storage resource, the paper initially proposed a model of data accessing, data sharing and access control, which is realized in the Global Distributed Storage System (GDSS). This model expands the standard FTP (File Transfer Protocol) protocol to define the GDSP (Global Distributed Storage Protocol) protocol, which uses the XML (eXtensible Markup Language) documents to encapsulate metadata of subjects and resources in storage system. GDSP defines functions which are not supported by FTP protocol such as data sharing, data searching, third-part-transfer, multi-part-transfer and so on. In GDSS system, the SSP server and the specific client realizes these functions, and in the client side, you can access distributed data resources conveniently and transparent through many kinds of way.According to the characteristic of how storage users use storage resource in WAN (Wide Area Network), the model gives a well-defined uniform description of storage resources and subject that use them. Base on this definition, the model give the concept of in-out-sharing, group-sharing, and also the data sharing mechanism which integrate them. At the same time, the model defines and implements a multi-layered uniform naming space. The model uses an access mechanism which combines the use of many distributed Storage Service Point and access ticket and is used in WAN which contains many autonomous domains. Such a mechanism can implement single-sign-on in WAN, and increase the efficiency of storage service. Fatherly, the model uses the ticket-based access control and extended ACL to implement the QoS of storage service.