Algorithms and Data Structures for Efficient Free Space Reclamation in WAFL

Authors: 

Ram Kesavan, Rohit Singh, and Travis Grusecki, NetApp; Yuvraj Patel, University of Wisconsin—Madison
Awarded Best Paper!

Abstract: 

NetApp®WAFL®is a transactional file system that uses the copy-on-write mechanism to support fast write performance and efficient snapshot creation. However, copy-on-write increases the demand on the file system to find free blocks quickly; failure to do so may impede allocations for incoming writes. Efficiency is also important, because the task may consume CPU and other resources. In this paper, we describe the evolution (over more than a decade) of WAFL’s algorithms and data structures for reclaiming space with minimal impact on the overall storage appliance performance.

Open Access Media

USENIX is committed to Open Access to the research presented at our events. Papers and proceedings are freely available to everyone once the event begins. Any video, audio, and/or slides that are posted after the event are also free and open to everyone. Support USENIX and our commitment to Open Access.

BibTeX
@inproceedings {202319,
author = {Ram Kesavan and Rohit Singh and Travis Grusecki and Yuvraj Patel},
title = {Algorithms and Data Structures for Efficient Free Space Reclamation in {WAFL}},
booktitle = {15th USENIX Conference on File and Storage Technologies (FAST 17)},
year = {2017},
isbn = {978-1-931971-36-2},
address = {Santa Clara, CA},
pages = {1--14},
url = {https://www.usenix.org/conference/fast17/technical-sessions/presentation/kesavan},
publisher = {USENIX Association},
month = feb
}

Presentation Audio