HaRD: The Wisconsin Hierarchically-Redundant, Decoupled Storage Project

威斯康星州分层冗余、解耦存储项目（HaRD）研究了用于混合闪存/磁盘存储群集的下一代存储软件。该项目的主要目标是在各种不同的场景中提高存储性能，包括新的应用程序环境，如Facebook和Flickr中的照片存储，政府实验室中的高端科学处理，以及Google和Microsoft中的大规模数据处理。为了提高这些重要应用程序的性能，HaRD项目集中在三个关键问题上：客户端基于闪存的RAID和文件系统集成，服务器端内存减少和多核调度系统任务，以及计划的网络传输。HaRD通过三个目标存储系统将这些技术整合为一个综合整体：可扩展的照片服务器，高性能检查点子系统和用于MapReduce工作负载的改进文件系统。该项目的影响是显著的，因为HaRD有助于塑造下一代云计算服务的存储软件架构，这与整个行业和社会的相关性越来越大。

The Wisconsin Hierarchically-Redundant, Decoupled storage project (HaRD)investigates the next generation of storage software for hybrid Flash/diskstorage clusters. The main objective of the project is to improve theperformance of storage in a variety of diverse scenarios, including newapplication environments such as photo storage as found in Facebook andFlickr, high-end scientific processing as found in government labs, andlarge-scale data processing such as that found in Google and Microsoft. TheHaRD project focuses on three key issues in order to improve performance ofthese important applications: client-side Flash-based RAID and file-systemintegration, server-side memory reduction and multicore scheduling offile-system tasks, and scheduled network transfers. HaRD pulls together thesetechnologies into a synthesized whole through three targeted storage systems:a scalable photo server, a high-performance checkpoint subsystem, and animproved file system for MapReduce workloads. The impact of this project issignificant, as HaRD helps to shape the storage software architecture of thenext generation of cloud computing services, which are of increasing relevanceto both industry and society at large.