A Method of Solving Data Consistency of Disk Array Cache

In order to raise speed of reading data from disk array memory, scientific and technological personnel have introduced cache technology into disk array. Since this technique has been invented, although the efficiency of reading data have been solved, after writing operation of countless times in disk cache, data consistency problem has been prominent expression. Especially in this condition that false of electricity and machine abnormal failure, the consistency of the data is more difficult to guarantee. In this paper, we adopt Non-Volatile RAM (NVRAM) devices to realize that the data will not be lost in disk array cache after power failure. Here we design a kind of new cache organizational structure. We firstly introduce cache structure of two tables (real-time mapping table, backup mapping table) and a cache backup block. Then through these two tables, we can work to recover data through the copy between the two tables in the macroscopic, and in the microscopic through cache backup block can backup the cache data from writing failure. As power failure and system breakdown, we can ensure that data will not easily lose and the original data can recovery after system crash by this technology. Thus it ensures the consistency of the data cache.