SHF: Small: Redesigning the System Architecture for Ultra-High Density Data Storage

计算机存储系统正朝着极高密度发展。随着采用先进的10纳米制造工艺构建的四层单元（QLC）和3D垂直NAND等新兴存储技术的出现，在不久的将来，一台服务器将能够容纳PB级的数据。这种前所未有的存储密度增长使我们能够以低成本构建高度整合的服务器系统，但与此同时，它也带来了可扩展性，可靠性和可共享性方面的各种关键挑战。简单地将现有的系统堆栈移植到大量压缩的存储上将创建一个严重不平衡的系统-尽管存储能够容纳大量数据，但系统堆栈中未优化的硬件和软件组件无法有效可靠地管理和交付数据。因此，存储密度的增长应被视为一个根本的系统变化，这需要对整个系统堆栈进行全面的重新评估。本项目系统地研究了这些具有挑战性的研究问题，通过使用一种内聚的方法来重新考虑存储系统体系结构设计的不同层次。该项目还旨在通过在研究活动中培训学生，为教育活动做出贡献，并向K-12学生推广，以增加其影响力。该项目通过采用整体，跨层，全系统的方法来优化计算机系统层次结构中的多个层，以解决关键的技术挑战。 具体而言，该项目研究了存储架构设计中的各个重要方面，以重新平衡高度压缩存储的系统，例如重新考虑I/O效率的映射结构，利用QLC闪存和非易失性存储器进行有效的数据管理，将计算密集型存储操作卸载到硬件加速器。该项目还研究了系统堆栈中的中间层，以管理硬件并提供简化的语义丰富的存储服务。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Computer storage systems are advancing towards extremely high density. With emerging storage technologies, such as Quad-Level Cell (QLC) and 3D vertical NAND, built using advanced 10 nanometer manufacturing processes, one single server will be able to accommodate petabytes of data in the near future. Such an unprecedented storage density growth allows us to build highly consolidated server systems at low costs, but in the meantime, it also brings a variety of critical challenges in terms of scalability, reliability, and shareability. Simply transplanting the existing system stack onto vastly condensed storage would create a severely unbalanced system - although the storage is able to accommodate a huge amount of data, the unoptimized hardware and software components in the system stack are unable to efficiently and reliably manage and deliver the data. Thus, the growth of storage density should be regarded as a fundamental system change, which demands a full-scale re-assessment on the whole system stack. This project systematically studies these challenging research issues by using a cohesive approach to reconsider the storage system architecture design at different levels. This project also aims to increase its impact by training students in research activities, contributing to educational activities, and outreach to K-12 students.The project addresses the critical technical challenges by adopting a holistic, cross-layer, whole-system approach for optimizations across multiple layers in the computer system hierarchy. Specifically, the project investigates various important aspects in the storage architecture design to re-balance the system for highly condensed storage, such as reconsidering the mapping structure for I/O efficiency, leveraging the QLC flash storage and non-volatile memory for efficient data management, offloading computationally intensive storage operations to hardware accelerators. The project also studies the intermediate layers in the system stack to manage hardware and provide simplified, semantic-rich storage services. A set of key data-intensive applications is further studied for effectively leveraging the next-generation high-density storage.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.