The Research And Implementation Of ISCSI Network RAID Based On Embedded Platform

With the rapid development of network technology and computer technology, the global digitization has brought the explosive growth of digital information. A large amount of data has been accumulated in the process of informatization by companies and government important departments. However, as the main storage device, it is difficult for hard disk to shake off the system performance bottleneck, and it is very limited to improve the disk performance greatly based on the current hard disk technology. Moreover there are lots of data security problems for hard disk storage. RAID(Redundant Arrays of Independent Disks) is a kind of multi-disk data storage system. It is based on the current hard disk technology and can improve storage performance and data security, it has become the mainstream storage technology.RAID, as the basis of network storage, can improve the data throughput of the storage system by writing and reading data simultaneously in a number of hard disks. RAID can provide fault tolerance by data check disk, RAID has higher security than hard disk. However, traditional centralized RAID has the disadvantage of poor disaster recovery. This thesis provided a network RAID solution in order to overcome the disadvantage of poor disaster recovery of traditional centralized RAID.RAID technology is analyzed and researched in this thesis firstly, including the definition of RAID, the classification of RAID and realization methods of RAID. This paper emphasized on the realization mechanism of the software RAID deeply in Linux kernel. The definition of network RAID was discussed primarily.iSCSI(Internet Small Computer System Interface) is a protocol which transports SCSI commands and data through IP network. The iSCSI protocol was researched deeply next, including working principle of iSCSI and some aspects of iSCSI. The working principle of network based on iSCSI protocol was analyzed deeply in Linux kernel.Then this paper provided a network RAID solution, which is called iSCSI network RAID based on embedded platform and described the process of building the platform in detail, including the target platform based on embedded platform and the initiator platform.Finally the author conducted a simulation experiment. Due to network factors, for example network delay, the performance of network RAID would decline to a certain extent compared with centralized RAID. This thesis tested and recorded the performance data of centralized RAID and network RAID in a variety of different test situations, compared the performance difference in the same situation between centralized RAID and network RAID and analyzed the test data in detail. The purpose of the simulation experiment is to analyze the extent of performance degradation of network RAID and came to a conclusion of the feasibility that sacrificing the limited extent of the performance is in exchange for higher disaster recovery.