CS Events

Computer Science Department Colloquium

White-Box Optimization Approaches for Ultra-Large-Capacity NAND Flash-Based SSDs

 

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Thursday, October 31, 2024, 01:00pm - 02:30pm

 

Speaker: Assistant Professor Jisung Park

Bio

Jisung Park is an Assistant Professor in the Department of Computer Science and Technology at POSTECH, where he leads the Computer Architecture and Operating Systems (CAOS) Laboratory. Jisung is also affiliated with the Graduate School of Artificial Intelligence. Before joining POSTECH in 2022, Jisung spent three years working as a Senior Researcher and Lecturer in the Department of Information Technology and Electrical Engineering at ETH Zürich. Jisung earned his Ph.D. degree in Electrical Engineering and Computer Science and B.E. degree in Computer Science and Engineering from Seoul National University. Jisung's research interests span a wide range of computer systems fields, including computer architecture, system software, and embedded systems, with a special focus on memory and storage systems, system security, and HW/SW cooperation.

Location : CoRE 301

Event Type: Computer Science Department Colloquium

Abstract: This talk discusses potential challenges in designing ultra-large-capacity NAND flash-based SSDs and introduces two white-box optimization approaches to address the challenges. NAND flash memory is the predominant technology for modern storage systems to meet the high-performance and large-capacity storage requirements of data-intensive applications. As a promising solution to reduce the total cost of ownership (TCO) of storage systems, there is increasing demand for ultra-large-capacity SSDs that offer unprecedented single-device storage capacity (e.g., 128 TB). Even though some manufacturers have recently introduced their successful development of such large-capacity SSDs, there exist new technical challenges that need to be addressed to achieve high I/O performance and long SSD lifetime, which primarily originate from the reliability issues of high-density NAND flash memory. In this talk, I will present two recent works, each of which effectively improves the performance and lifetime of high-density NAND flash-based SSDs, respectively, based on a deep understanding of underlying hardware components. Such white-box optimization approaches can effectively overcome the limitations of conventional black-box approaches, unlocking the full potential of NAND flash memory. First, I will introduce RiF (Retry-in-Flash), an in-flash processing technique to identify a read failure inside a NAND flash chip, which can avoid the waste of SSD-internal bandwidth due to read retry. Second, I will present AERO (Adaptive ERase Operation), which dynamically adjusts the erase latency to be just enough for reliable operation, thereby enhancing SSD lifetime by minimizing the erase-induced cell stress.

Contact  Assistant Professor Minesh Patel