首尔国立大学Jihong Kim教授来我院开展讲座

2012年6月26日下午，在海韵行政楼C座505报告厅，首尔国立大学Jihong Kim教授开展了一场主题为Improving SSD Lifetime Using Compression, Deduplication and Performance Throttling（运用压缩，重复数据删除和性能调节的方法提高SSD使用寿命）的讲座。

Jihong Kim是首尔国立大学计算机科学与工程学院教授。在到首尔国立大学之前，他是在得克萨斯州达拉斯仪器的DSP研发中心工作的一名技术人员。Jihong Kim在1986年从首尔国立大学取得计算机科学和统计学学士学位，并于1988年和1995年在华盛顿大学取得计算机科学与工程的硕士和博士学位。他同时是IEEE计算机协会和ACM的成员。 他的研究兴趣包括低功耗系统，基于NAND闪存的存储系统，计算机架构和移动计算。

我院王琳副院长担任本场讲座主持人，在讲座中，Jihong Kim教授首先介绍了首尔国立大学的计算机科学与工程学院，自己的研究概况以及今后的技术导向，接着介绍了NAND闪存和它的三个特性：1.不对称的运行性能；2.不支持进行原位更新；3.有限的性能。然后详细讲述了SDD的软件，硬件特点，影响SDD使用寿命的四个因素：1.FTL的设计效率；2.SDD的容量；3.写流量；4.编程/擦除（P/E）周期数。针对各项因素分别介绍了改进方法，如：减少经过SDD的写流量，无损数据压缩，重复数据删除，动态性能限制等。同时，Jihong Kim教授还阐述了未来该领域所要研究的两个问题：整合提出的技术的最佳途径是什么，真正的磨损指标是什么。Jihong Kim教授的讲座逻辑严谨，层次分明，运用丰富的数据图表资料展示出SDD各项性能的概况，并在讲座结尾细致认真地和听众们进行问答交流。此次讲座让大家深入浅出的了解到该领域的研究工作，开阔了视野，受益匪浅，本次讲座在热烈的掌声中落下帷幕。

                                                    （我院宣传中心  汪恒一）

【海韵讲座第17场】

讲座题目：

Improving SSD Lifetime Using Compression, Deduplication and Performance Throttling

讲座时间：

6月26日（周二）下午4：00

讲座地点；

海韵园行政楼C505报告厅

讲座人：

Prof. Jihong Kim

Computer Architecture and Embedded Systems Laboratory (CARES)

School of Computer Science & Engineering

Seoul National University

Seoul, Korea

Jihong Kim is a Professor in the School of Computer Science & Engineering, Seoul National University. Before joining Seoul National University, he was a Member of Technical Staff in the DSPS R&D Center of Texas Instruments in Dallas, Texas.

Jihong Kim received his BS in computer science and statistics from Seoul National University in 1986, and MS and PhD degrees in computer science and engineering from the University of Washington in 1988 and 1995, respectively.

His research interests include low-power systems, NAND flash-based storage systems, computer architecture and mobile computing. He is a member of the IEEE Computer Society and ACM.

讲座摘要：

NAND flash-based solid-state drives (SSDs) are increasingly popular in enterprise server systems because of their advantages over hard disk drives such as higher performance and lower power consumption. However, the limited and unpredictable lifetime of SSDs remains to be a serious obstacle to wider adoption of SSDs in enterprise systems.

In this talk, we present our experiences of developing three SSD lifetime management schemes, lossless data compression, deduplication, and performance throttling.  In order to improve the lifetime of SSDs, the data compression and deduplication schemes try to minimize the amount of data written to SSDs while the performance throttling scheme regulates the write speed of SSDs by delaying write operations when necessary. We have developed BlueZIP, a hardware-accelerated compression module, FineDedup, a fine-grained data deduplication module, and, READY, a novel recovery-aware dynamic throttling technique.  After each scheme is presented, we will discuss our early results from combining all three schemes in an integrated fashion.

If time permits, I will briefly introduce other research activities at CARES, including our resecent work on personalized optimizations for smartphones.

信息科学与技术学院

2012年6月22日