Analyzing the feasibility of building a new mass storage system on distributed resources

摘要

The average PC now contains a large and increasing amount of storage with an ever greater amount left unused. We believe there is an opportunity for organizations to harness the vast unused storage capacity on their PCs to create a very large, low-cost, shared storage system. What is needed is the proper storage system architecture and software to exploit and manage the unused portions of existing PC storage devices across an organization and make it reliably accessible to users and applications. We call our vision of such a storage system Storage @desk (SD). This paper describes our first step towards the realization of SD-a study of machine and storage characteristics and usage in a model organization. We studied 729 PCs in an academic institution for 91 days, monitoring the configuration, load and usage of the major machine subsystems, i.e. disk, memory, CPU and network. To further analyze the availability characteristics of storage in an SD system, we performed a trace-driven simulation of some basic storage allocation strategies. This paper presents the results of our data collection efforts, our analysis of the data, our simulation results and our conclusion that an SD system is indeed feasible and holds promise as a cost-effective way to create massive storage systems.