On Benchmarking Embedded Linux Flash File Systems

TL;DR

This paper evaluates the performance of popular embedded Linux flash file systems, revealing significant disparities in operation efficiency due to their handling of flash memory characteristics.

Contribution

It provides a comprehensive performance comparison of JFFS2, UBIFS, and YAFFS, highlighting their unique behaviors and efficiency differences in embedded Linux environments.

Findings

Large performance disparities among tested FFSs

Distinct behaviors in mounting, copying, and searching operations

Performance impacts due to flash memory management strategies

Abstract

Due to its attractive characteristics in terms of performance, weight and power consumption, NAND flash memory became the main non volatile memory (NVM) in embedded systems. Those NVMs also present some specific characteristics/constraints: good but asymmetric I/O performance, limited lifetime, write/erase granularity asymmetry, etc. Those peculiarities are either managed in hardware for flash disks (SSDs, SD cards, USB sticks, etc.) or in software for raw embedded flash chips. When managed in software, flash algorithms and structures are implemented in a specific flash file system (FFS). In this paper, we present a performance study of the most widely used FFSs in embedded Linux: JFFS2, UBIFS,and YAFFS. We show some very particular behaviors and large performance disparities for tested FFS operations such as mounting, copying, and searching file trees, compression, etc.