Wei-Shen, Hsu 2013 IEE5011 –Autumn 2013 Memory Systems Solid State Drive with Flash Memory Wei-Shen, Hsu Department of Electronics Engineering National Chiao Tung University

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Outline Introduction An Overview of SSD Drive The Architecture of SSD The Benefit of SSD Drive Flash Memory Storage Medium Flash Memory NAND Memory Operational Functions NAND Memory Management Operation Integrated Lifetime Management Target SSD Architecture Results Reference 2

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Introduction Why SSD? 3

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 An Overview of SSD Drive (1/3) SSD electrically, mechanically, and software compatible DRAM-Based SSDs volatile memory Flash-Based SSDs non-volatile memory 4

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 An Overview of SSD Drive (2/3) 5 The Architecture of SSD Array of Flash Memory Micro-Controller Memory Bus Data I/O Interface

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 An Overview of SSD Drive (3/3) 6 The benefit of SSD drive Without Moving Mechanical Components  Platters  Read/Write Head  Spindle Motor Silent Operation

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Flash Memory Storage Medium (1/5) NOR Flash Pros: random data accessibility, faster reading capability Cons: writing and erasing data NAND Flash Pros: large storage capacity, storing and erasing data Cons: random data accessing 7

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Flash Memory Storage Medium (2/5) NAND Memory Memory array I/O buffer Page Main storage area Spare area 8

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Flash Memory Storage Medium (3/5) NAND Memory Operational Functions Read : fetch the required data Write : 1 → 0 Erase : 0 → 1 Three Phases: setup, busy, and data transfer 9

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Flash Memory Storage Medium (4/5) Three Access Operations Phases Setup Phase  determine a targeted page address Busy Phase  loading the required data into the I/O buffer Data Transfer Phase  sequentially fetch data 10

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Flash Memory Storage Medium (5/5) NAND Memory Management Operation Out-Place Updating  the newest updated data is written to some available free page Garbage Collection  change the dead pages into free pages Wear-Levelling  control the block erasing operation to increase the block lifetime 11

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Target SSD Architecture Lifetime-Enhancement Techniques Lossless Compression Data Deduplication Performance Throttling 12

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Integrated Lifetime Management (1/4) Integration of Individual Lifetime-Enhancement Schemes interval-based approach  enable or disable each lifetime-enhancement scheme 13

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu Integrated Lifetime Management (2/4) Deduplication

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Lossless Compression Compression Chunk 15 Integrated Lifetime Management (3/4)

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Performance Throttling Delay write operations  determines a throttling delay  regulates the write speed of SSDs 16 Integrated Lifetime Management (4/4)

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Results Throttling and Integrated that employ performance throttling can guarantee the 5-year SSD lifetime. 17

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Reference A. R. Rahiman and P. Sumari, "Solid State Disk: A New Storage Device for Video Storage Server, " in ITSim 2008 of International Symposium on Information Technology, Sungjin Lee, Taejin Kim, Ji-Sung Park, and Jihong Kim, "An Integrated Approach for Managing the Lifetime of Flash-Based SSDs," in Design, Automation & Test in Europe Conference & Exhibition (DATE), W.G. Aref, I. Kamel, and S. Ghandeharizadeh, "Disk scheduling in video editing systems," IEEE Transactions on Knowledge and Data Engineering, vol. 13, pp , D. Reinsel, J. Janukowicz, and R. Perry, "Replacing HDDs with SSDs: The Business Case for Transition," F. Chen, T. Luo, and X. Zhang, "CAFTL: A Content-Aware Flash Translation Layer Enhancing the Lifespan of Flash Memory Based Solid State Drives," in Proceedings of the USENIX Conference on File and Storage Technologies, Y. Park and J.-S. Kim, "Compression Support for Flash Translation Layer," in Proceedings of the International Workshop on Software Support for Portable Storage, D. Kang, 1.-S. Kim, C. Park, H. Park, and 1. Lee, "A multi-channel architecture for high-performance NAND flash-based storage system," Journal of Systems Architecture, vol. 53, pp , S. Lee, T. Kim, K. Kim, and J. Kim, "Lifetime Management of Flash-Based SSDs Using Recovery-Aware Dynamic Throttling," in Proceedings of the USENIX Conference on File and Storage Technologies,

NCTU IEE5011 Memory Systems 2013Wei-Shen, Hsu 2013 Thank you for your attention 19