A New Kind of Storage Hierarchy-Volume Holographic Universal Storage Cache

摘要

The access time of Disk/RAID has not been improved as fast as the memory performance whose rate of improvement has been 25% per year and hence the disk access penalty is considerably increasing with each enhancement in the memory architecture. To solve the problem, a new kind of storage hierarchy - Volume Holographic Universal Storage Cache (short for VHUSC) is proposed. VHUSC acts as a layer between main memory and disk or disk array. VHUSC can lower the disk access latency, provide much higher I/O bandwidth and throughput, it thus greatly improve the I/O performance of computer system. In this paper, an application independent model based on queuing theory is proposed for the VHUSC performance evaluation. Based on this model, VHUSC and traditional disk/RAID performance is analyzed and compared. Result shows that in most cases VHUSC can improve the disk read/write performance by 1 order of magnitude, especially when the hit rate is larger than 99%, the performance can reach 2 orders of magnitude.