FDPFS: Leveraging File System Abstraction for FDP SSD Data Placement

Abstract

Flexible data placement (FDP) is an emerging interface within the NVM express (NVMe) storage standard, aiming to decrease write amplification factor (WAF) in solid state drives (SSDs) through explicit user-controlled data placement. Currently, the FDP ecosystem burdens embedded software programmers with low-level systems programming to efficiently deploy FDP SSDs. We propose FDPFS, a file system that elevates the abstraction to file systems by exposing FDP SSDs as directories to which programmers can easily group and direct semantically similar data for user-controlled data placement. Under the hood, FDPFS performs the tedious low-level tasks of interfacing and assigning these semantically grouped data to different SSD erase blocks to reduce WAF, and improve overall SSD performance and lifetime. Our case study on the filebench benchmark demonstrates that our FDPFS prototype not only eases explicit data placement, but also yields up to 34% reduction in the SSD WAF which promises improved overall performance and lifetime of the SSD.