Systems Seminar

EPFL IC Systems Seminar

Scalability, Fairness, and Availability in Modern Storage Systems: Challenges, Solutions, and Outlook


The storage subsystem is a fundamental performance bottleneck in running data-intensive enterprise and cloud applications. Recent system design, application, and technology trends that require more storage capacity, I/O bandwidth, performance predictability, and data availability out of the storage subsystem make it an even more important system bottleneck. At the same time, non-volatile memories (NVMs), as the basic building blocks of the modern high-performance storage devices, are experiencing serious technology scaling challenges that make the maintenance and enhancement of their performance and capacity significantly costly with conventional design techniques.

In this talk, we first discuss major challenges facing modern storage systems in the presence of increasing demand for lower data access time and higher storage capacity. We then discuss our proposed solutions to alleviate these challenges. We will touch on several key topics: 1) scalability challenges of modern flash-based storage systems and our novel solution to address these challenges, 2) how to accurately model the new sophisticated features of modern SSDs such as the NVMe host interface protocols, 3) unfairness and quality-of-service issues of modern off-the-shelf Solid-State Drives (SSDs) in shared environments, 4) enabling fair and high-performance I/O request scheduling in modern NVMe SSDs, 5) fault-tolerance and data availability challenges of modern NVM-based main memories, 6) enabling high-availability for NVM-based main memories via two novel efficient data replication techniques.


Arash is a senior software engineer at RepRisk AG, Zurich, where he is working on modern data analytics infrastructures. His research interests are high-performance and scalable storage system design, architectures for big data analysis, and near data processing. Arash graduated with a Ph.D. from Sharif University of Technology, Tehran, Iran in 2015 and spent two years (2016-2018) as a Postdoc at Systems Group, ETH Zurich. Arash also has more than ten years of experience in high-performance computing and design issues of scale-out data centers. He was one of the founding members and the technical manager of the High-Performance Computing Laboratory at Institute for Research in Fundamental Sciences (IPM), Tehran, Iran, where the most powerful Iranian supercomputer was built on 2008 using modern heterogeneous multicore processors.