CRII: CSR: Rethinking the FTL in SSDs -- a file translation layer instead of a flash translation layer

随着人工智能、网络服务和云存储数据集的增长，对存储设备数据快速高效服务的需求也在增长。使用基于非易失性的固态硬盘（ssd），闪存技术是提高存储设备性能的有效途径。然而，由于计算机系统的其余部分利用根深蒂固的接口与ssd通信，因此支持这些抽象的开销掩盖了ssd的真正潜力。具体来说，不同系统层的不同寻址模式导致在访问单个文件时进行多次地址转换，并且需要额外的系统资源来维护映射。这种地址转换开销既费时又限制了ssd的带宽。这个项目通过提出一个创新的存储接口来解决这个问题，该接口可以最大限度地减少系统开销，但更适合应用程序访问数据的行为。所提出的接口将简化操作系统的设计。此接口不需要对现有应用程序进行修改。由于大多数文件访问开销来自操作系统，因此使用建议的接口简化操作系统将显著提高应用程序访问ssd时的延迟和带宽。该项目将在不改变现有硬件的情况下在真实的ssd中实施拟议的设计，这意味着该项目的结果可以立即促进现有计算机系统托管大数据应用，而无需额外的硬件成本。该项目还将鼓励研究人员重新审视现有的硬件/软件接口，以在新兴的外围设备上实现更好的性能，并探索其他好处，包括增强安全性和降低能耗。

As data sets for artificial intelligence, network services, and cloud storage grows, so does the demand of quickly and efficiently serving data from the storage device. Using solid state drives (SSDs) based on non-volatile, flash memory technologies is an effective approach to improve the performance of storage devices. However, as the rest parts of the computer system leverage the entrenched interface to communicate with SSDs, the overhead of supporting these abstractions buries the real potential of SSDs. Specifically, the different addressing modes for different system layers result in multiple address translations when accessing a single file and require additional system resource to maintain the mapping. This address translation overhead takes time and limits the bandwidth of SSDs. This project is addressing this problem by proposing an innovative storage interface that minimizes the system overhead but better fits the behaviors of applications in accessing data. The proposed interface will simplify the design of operating systems. This interface will require no modifications to existing applications. As most file accessing overhead coming from the operating system, simplifying operating systems with the proposed interface will significantly boost the latency and bandwidth when applications access SSDs. This project will implement the proposed design in real SSDs without changes to existing hardware, meaning that the result of this project can immediately facilitate existing computer systems hosting big data applications without additional hardware costs. This project will also encourage researchers to revisit existing hardware/software interfaces for achieving better performance on emerging peripheral devices as well as exploring other benefits, including enhanced security and reduced energy consumption of pursuing this research direction.