Research Of The Struture Design Of Hybrid Hard Disk And Its Key Technology

The technology of hybrid hard drive combines the huge capacity peculiarity of hard disk and rapidity and low power consuming of FLASH. To the mobile computing device, the problem that The using time of the battery is so short is fatal,however, the low power comsuming of the technology of hybrid hard drive can slove the problem well. At the same time it can improve the performance of the computing equipment, for example, the speed of the set up and the power down, the start-up time of the programme in common use and the speed of accessing data.The hybrid hard drive is the organic combine of the traditional hard disk and the flash.The flash is being the cache between the main storage and the traditional hard disk. The users can put the often used program and data in flash but not in traditional hard disk. The system utilize the emdebed developing board UP-NETARM2410S of BoChuang Corporation as the devoloping enviroment to simulate the hybrid hard drve. The system utilize the embeded developing technology, combine the theory of the cache of the hard disk, handle the traditional hard disk and flash through the technology of ARM9 and the embeded operation system UCOSII, the reading and writing operations towards the disk and flash, and the data exchange of the disk and flash. The space of flash is divided into pre-reading cache and writing cache, the data searching is through the hash algorithm to improve the efficiency. To improve the hit rate of reading operation, we adopt different pre-reading algorithm according different data characteristic, and adopt the LFU(least frequency used)algorithm for the replacing algorithm.the write request is redicted to the flash, write to the disk until reach a amount. We improve the traditional spin-down algorithm, such as intelligent spin-down algorithm, read cache missing,pre-spin-up. These mesures can lengthen the time that the disk is spun-down to reduce the power consuming. This technology can improve the efficiency of the storage system, reduce the power consuming, improve anti-shaking and stability.This technology has shown some superority,hybrid hard drive exceeds the traditional hard disk on performance,low-powe-consuming,anti-shaking, stability. And we believe that this technology will have a good forground.