BetrFS: Write-Optimization in a Kernel File System

Donald Porter, Stony Brook University
Host: Yair Amir

Write-optimized dictionaries (WODs) are a promising building block for storage systems because they have the potential to strictly dominate the performance of B-trees and other common on-disk indexing structures. In particular, WODs can dramatically improve performance of both small, random writes and large, sequential scans, without harming other operations.

This talk will introduce the basics of write-optimization and the B^\epsilon tree, and will then describe BetrFS, the first in-kernel write-optimized file system. BetrFS contributes a combination of kernel-level techniques to leverage write-optimization in the VFS layer and data structure-level enhancements to meet the requirements of a POSIX file system. Compared to commodity file systems, such as ext4 and xfs, BetrFS can improve performance by up to orders of magnitude, and generally matches other file systems in the worst cases.

Speaker Biography

Don Porter is an Assistant Professor and Kieburtz Young Scholar of Computer Science at Stony Brook University. Porter’s research interests broadly involve improving efficiency and security of computer systems. Porter earned a Ph.D. and M.S. from The University of Texas at Austin, and a B.A. from Hendrix College. He has received awards including the NSF CAREER Award and the Bert Kay Outstanding Dissertation Award from UT Austin.