Introduction to the Special Section on USENIX FAST 2020

Abstract

Every year, the storage and file system community convene at the USENIX Conference on File and Storage Technologies (FAST) to present and discuss the best of the exciting research activities that are shaping the area. In February of 2020, luckily just before the rampant spread of COVID-19, we were able to do the same for the 18th USENIX Conference on File and Storage Technologies (FAST’20) at Santa Clara, CA. This year, we received 138 exciting papers, out of which 23 papers were selected for publication. As in previous years, the program covered a wide range of topics ranging from cloud and HPC storage, key-value stores, flash and non-volatile memory, as well as long standing traditional topics, such as file systems, consistency, and reliability. In this Special Section of the ACM Transactions on Storage, we highlight three high-quality articles that were selected by the program chairs. These select articles are expanded versions of the FAST publications (and re-reviewed by the original reviewers of the submission) that include material that had to be excluded due to the space limitation of conference papers, allowing for a more comprehensive discussion of the topic. We are confident that you will enjoy these articles even more. The first article is “Reliability of SSDs in Enterprise Storage Systems: A Large-scale Field Study” (titled “A Study of SSD Reliability in Large-scale Enterprise Storage Deployments” in the FAST’20 Proceedings) by Stathis Maneas, Kaveh Mahdaviani, Tim Emami, and Bianca Schroeder. This article was submitted as a Deployed systems paper, and it presents a large-scale field study of 1.6 million NAND-based SSDs deployed at NetApp. This article is the first study of an enterprise storage system, which comprises a diverse set of SSDs from three different manufacturers, 18 different models, 12 different capacities, and all major flash technologies from SLC to 3D-TLC. The second article is “Strong and Efficient Consistency with Consistency-aware Durability” by Aishwarya Ganesan, Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, and Remzi H. ArpaciDusseau. This article introduces consistency-aware durability or CAD, which is a new approach to durability in distributed storage, and a novel and strong consistency property called cross-client monotonic reads. The authors show that this new consistency property can be satisfied with CAD by shifting the point of durability from writes to reads. Through an implementation study, the authors show that the two notions combined can bring about performance significantly higher than immediately durable and strongly consistent ZooKeeper, even while providing stronger consistency than those adopted by many systems today. The final article is “Copy-on-Abundant-Write for Nimble File System Clones” (originally titled “How to Copy Files”) by Yang Zhan, Alex Conway, Yizheng Jiao, Nirjhar Mukherjee, Ian Groombridge, Michael A. Bender, Martin Farach-Colton, William Jannen, Rob Johnson, Donald E. Porter, and Jun Yuan. This article presents how to clone files and directories, which is an important operation in many real-world applications and workflows, in the write-optimized BetrFS file system. The key observation of the article is that write-optimized key-value stores, such as the Bɛ-tree or