Adapting byte addressable memory storage to user-level file system services

Abstract

Widely available distributed file systems for big data processing are implemented as user-level services since the existing file systems, which are implemented in the operating system kernel, cannot satisfy their requirements. They usually employ file systems in the kernel to persistently save their data in their local systems; thus, the kernel is always interposed for their access the storage devices. Now, next generation non-volatile memory technologies are emerging as byte addressable memory devices that can be used as high performance storage, for which the interposition of the kernel is the source of overhead. This paper proposes the adaption of memory storage to user-level file system services and the convergence of such services and memory storage. User-level file system services are connected to memory storage through the library implementation of a file system, and a library file system can directly interact with memory storage through the memory interface by mapping memory storage onto a user process address space. We implemented a library file system on Linux. The experiment results show that the the implemented library file system outperforms the existing file system in the kernel and performs 1.9x and 6.5x faster for reading and writing, respectively, for typical cases.