Research On Key Technologies Of Biological Immunity-Inspired Network-Attached Storage

The exploded increase in volume of digital information promotes the research of storage and processing technologies for data recorded with CDs and disks. It is important for large number of data to be stored reliably and utilized effectively. With the rapid development of network, the mode of data storage presents decentralized tendency increasingly. In traditional storage mode, the server plays a role of center and highly centralizes preservation of massive data and access to them, which easily incurs the serious I/O bottleneck on the server. Moreover, scalability, manageability and survivability are not well supported in the centralized storage framework. Therefore, it is necessary to research new schemes of network application for storage subsystem.Firstly, according to the decentralized tendency of data storage, the conventional C/S mode is broken, and modularized network-attached storage (NAS) devices are designed to act as data storage nodes in LAN of enterprises. For the modularization of structure, NAS devices are easy to be distributed and utilized in network. The optimized OS based on Linux has high efficiency and scalability, and supports multiple platforms, which improves the adaptability of devices to changes in network conditions. The manageability of devices is well supported by Web-based management manner.Secondly, aiming at the weakness of access security in present NAS products, the defending strategy of NAS devices is researched. Through the analysis of the access behaviors of users in NAS devices, the characteristics of sequence information in processes of file requests are studied. Scheduling of processes and realization of system calls are carefully researched, and an experiential formula of time for file requests is summarized. Then, inspired by biological immune mechanisms, a multilevel immune model, composed of user authentication, access authority of file system and user stair, is presented to enhance the security of data stored in NAS devices. The performance of model is analyzed from delay-time of processes by the experiential formula. This multilevel immune model realizes the abnormity detection and automatic immunity to users' operations, which enhances the availability and security of data in NAS devices.Based on the research mentioned above, a NAS file server with function of immunity is realized. The experimental results of I/O performance evaluation indicate that this NAS device has observably high throughput when multiple clients call it at the same time. Further more, the performance slowdown of file reading/writing is less than 2% after implementing of multilevel immune model. The research on biological immunity-inspired NAS devices provides a new scheme of network application for massive data storage subsystem, and makes the decentralized storage nodes have excellent performance, availability, scalability, and manageability.