The Full Path to Full-Path Indexing


Yang Zhan, The University of North Carolina at Chapel Hill; Alex Conway, Rutgers University; Yizheng Jiao, The University of North Carolina at Chapel Hill; Eric Knorr, Rutgers University; Michael A. Bender, Stony Brook University; Martin Farach-Colton, Rutgers University; William Jannen, Williams College; Rob Johnson, VMware Research; Donald E. Porter, The University of North Carolina at Chapel Hill; Jun Yuan, Stony Brook University


This paper shows how to use full-path indexing in a file system to realize fast directory scans, writes, and renames. Prior results indicated that renames are prohibitively expensive in full-path indexing.

The paper introduces a range-rename mechanism for efficient key-space changes in a write-optimized dictionary. This mechanism is encapsulated in the key-value-store API, and simplifies the overall design of the file system.

We implemented this mechanism in ArborFS, an extension of the BetrFS in-kernel, local file system for Linux. For instance, ArborFS performs recursive greps 1.5x faster and random writes 1.2x faster than BetrFS, but renames are competitive with standard, indirection-based file systems for a range of sizes. ArborFS outperforms relative-path file systems such as BetrFS as well as traditional file systems such as ext4, xfs and zfs across a variety of workloads.

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@inproceedings {210540,
author = {Yang Zhan and Alex Conway and Yizheng Jiao and Eric Knorr and Michael A. Bender and Martin Farach-Colton and William Jannen and Rob Johnson and Donald E. Porter and Jun Yuan},
title = {The Full Path to {Full-Path} Indexing},
booktitle = {16th USENIX Conference on File and Storage Technologies (FAST 18)},
year = {2018},
isbn = {978-1-931971-42-3},
address = {Oakland, CA},
pages = {123--138},
url = {},
publisher = {USENIX Association},
month = feb