CSR-PDOS: Energy-Efficient, High-Performance Storage Array Systems

高性能存储子系统所消耗的能量直接或间接地增加了用于I/O密集型应用的操作计算系统的成本。开发高能效的存储系统可以极大地降低购买和运营大型计算平台的成本，从而使它们对于广泛的计算问题具有成本效益。解决方案需要构建为现有存储系统技术(如RAID)的扩展。本研究通过设计和实现冗余感知的动态I/O调度算法、缓存管理软件和静态块分配算法来解决上述问题，这些算法为构建适用于要求苛刻的I/O密集型应用的节能高性能存储阵列奠定了基础。利用存储阵列固有的冗余性，通过功耗感知的请求调度/转换方案，在保证高性能的前提下，将磁盘访问模式向能效方向转变。深入研究了两种常用的存储阵列体系结构：镜像磁盘阵列和奇偶校验磁盘阵列。此外，还研究了一种扩展的RAID-混合存储阵列。研究的意义在于解决日益重要的高性能存储子系统的节能问题。它将通过提供节能的高性能存储解决方案在低功耗计算和I/O系统社区产生广泛影响，现代存储服务器、存储集群和数据中心都可以从中受益。在项目过程中，将向计算机系统社区交付高能效阵列及其扩展的变体混合存储阵列的原型版本。

The energy consumed by the high-performance storage subsystems increases the cost of operating computing systems for I/O intensive applications, both directly and indirectly. The development of energy-efficient storage systems can greatly reduce the cost of acquiring and operating large computing platforms, thereby making them cost-effective for a broad range of computational problems. Solutions need to be built as extensions to existing storage-system technologies such as RAID. This research addresses the above-mentioned problems by designing and implementing redundancy-aware, dynamic I/O scheduling algorithms, cache management software and static block distribution algorithms that serve as a foundation for building energy-efficient high-performance storage arrays for demanding I/O-intensive applications. The inherent redundancy of storage array is used to change the disk access pattern toward energy-efficiency with high-performance guarantee by power-aware request dispatch/transformation schemes. Two commonly used storage array system architectures, mirrored disk arrays and parity disk arrays are thoroughly studied. An extended variant of RAID-hybrid storage array is investigated as well. The significance of the proposed research is to solve the energy conservation problem for ever-important high-performance storage subsystems. It will have broad impact in the low-power computing and I/O systems community by providing an energy-efficient high-performance storage solution, which modern storage servers, storage clusters and data centers can benefit. During the course of the project, prototype versions of the energy efficient RAID and its extended variant-hybrid storage array will be delivered to the computer systems community.