CNS Core:Small: File System Offloading

计算机使用便于应用程序在存储设备中存储和访问数据的文件系统。文件系统驻留在受信任的操作系统(OS)中，实现对数据的一致、安全和持久访问。应用程序在不受信任的用户空间内运行，并且必须跨越受信任的操作系统边界才能使用文件系统访问存储硬件。在这个闪存和非易失性存储器等超高速存储技术的时代，跨越操作系统边界进行输入/输出(I/O)访问会导致较高的软件开销，并影响I/O和应用程序性能。因此，减少软件开销至关重要，但必须在不影响数据一致性、安全性和耐用性的情况下完成。该项目研究了高性能文件系统的重新设计，该文件系统允许应用程序直接绕过操作系统访问存储硬件，同时尊重崩溃一致性、安全性和持久性。该项目涉及三个研究项目。第一个推力确定负责崩溃一致性、安全性和耐用性的关键文件系统组件，并将它们卸载到存储硬件中，从而允许应用程序绕过操作系统。第二个推力探索了使用加速器加速卸载的组件以获得更高的性能。第三个推力重新设计卸载的组件，以利用设备电容等硬件功能来减少软件开销和提高崩溃一致性。通过重新设计存储软件，该项目有可能显著提高包括物联网(IoT)以及个人、数据中心和任务关键型系统在内的广泛应用程序的I/O性能，在这些应用程序中，无法运行商用操作系统。同样，开发的想法和原型将教育本科生、研究生和高中生，了解减少软件管理费用、在设计软件时了解硬件功能以及软硬件协同设计的好处。为了评估文件系统设计，该项目构建了一个软件原型和一个运行广泛的个人计算和数据中心应用程序的加速仿真器。研究出版物、带有文档的源代码和复制已公布的系统测量的说明将在罗格斯大学的(https://www.cs.rutgers.edu/~sk2113/fsoffload)网站上公布，并在项目期间维护。该奖项反映了美国国家科学基金会的法定使命，并已通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Computers use filesystems that facilitate applications to store and access data in a storage device. Filesystems reside inside a trusted Operating System (OS) and enable consistent, secure, and durable access to data. Applications run inside untrusted user space and must cross the trusted OS boundary for accessing storage hardware using filesystems. In this era of ultra-fast storage technologies such as flash and nonvolatile memory, crossing the OS boundary for input/output (I/O) access incurs high software overheads and impacts I/O and application performance. Therefore, reducing software overheads is critical but must be done without compromising data consistency, security, and durability.This project investigates the redesign of a high-performance filesystem that allows applications to access the storage hardware directly bypassing the OS, while respecting crash-consistency, security, and durability. The project involves three research thrusts. The first thrust identifies critical filesystem components responsible for crash-consistency, security, and durability and offloads them into the storage hardware allowing applications to bypass the OS. The second thrust explores the use of accelerators for accelerating offloaded components for higher performance. The third thrust redesigns offloaded components to exploit hardware capabilities such as device capacitance that can reduce software overheads and improve crash-consistency.By redesigning storage software, this project has the potential to significantly improve I/O performance for a wide domain of applications including Internet of Things (IoT) as well as personal, datacenter, and mission-critical systems where running commodity OS is not feasible. Equally, the ideas and prototypes developed will educate undergraduate, graduate, and high-school students on the benefits of reducing software overheads, understanding the hardware capabilities when designing software, and hardware-software codesign. To evaluate the filesystem design, the project builds a software prototype and an accelerated emulator running a wide-range of personal computing and datacenter applications. The research publications, source code with documentation, and the instructions for reproducing published measurement of the system will be made public and available from the Rutgers University's (https://www.cs.rutgers.edu/~sk2113/fsoffload) website maintained for the duration of the project.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.