Boosting Performance And Endurance Of Flash Based Storage Systems PDF Download
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| Author | : |
| Publisher | : |
| Total Pages | : 189 |
| Release | : 2015 |
| Genre | : Electronic books |
| ISBN | : |
Download Boosting Performance and Endurance of Flash-based Storage Systems Book in PDF, ePub and Kindle
NAND flash memory (hereafter, flash memory) has been intensively employed in a wide spectrum of computing systems from mobile devices like smartphones to personal computers to enterprise servers due to its high performance, low power consumption, and shock resistance. However, the further deployment of flash memory is impeded because it also possesses several inherent disadvantages such as limited programming/erase cycles and asymmetrical I/O performance. Besides, the existing frameworks for storage systems are originally designed for block devices (e.g., hard disk drives), which have totally different characteristics from flash memory. In order to utilize flash memory in current storage systems, an extra software layer between a traditional storage system interface and flash memory is needed to mimic the behavior of a block device. Unfortunately, using a flash-based storage system as a traditional HDD noticeably neutralizes the benefits of flash memory.In this dissertation, we holistically examine current flash-based storage systems in different computing platforms ranging from embedded systems to enterprise servers. Firstly, we empirically characterize a representative collection of flash memory devices and then model their raw I/O performance and reliability. Our results demonstrate that flash memory performance and reliability are correlated to programmed data patterns. Further, we propose multiple approaches to improving the performance and reliability of flash-based storage systems at device level. Secondly, we study flash translation layer (FTL) in flash-based solid-state drives (SSDs) for desktops. A plane-centric FTL and a workload-aware MLC/SLC (multi-level cell/single-level cell) partitioning scheme are implemented to boost the performance of a single SSD. Thirdly, the employment of SSD arrays in enterprise servers is investigated. We propose a load-balancing scheme at disk array level to prolong the lifetime of SSD arrays for server applications like OLTP (online transaction processing). Finally, an MTD (memory technology device) array based storage framework will be developed to meet the performance and reliability requirements demanded by emerging and future data-intensive and mission-critical mobile applications.
| Author | : Janak R. Koshia |
| Publisher | : |
| Total Pages | : 38 |
| Release | : 2011 |
| Genre | : |
| ISBN | : |
Download Boosting Random Write Performance of Enterprise Flash Storage Systems Book in PDF, ePub and Kindle
NAND flash memory is playing a key role in the revolution of storage systems due to its desirable features such as fast random read and high energy-efficiency. It has been extensively applied in mobile devices like smart phones and PDAs. With increasing capacity, throughput and durability, NAND flash memory based solid state disk (hereafter, flash SSD) has started replacing hard disk drive (HDD) in laptops and desktop systems. Employing high-end flash SSDs in server applications, however, is promising yet challenging. One of the challenges is that currently flash SSD cannot fully meet heavy random write requirements demanded by data-intensive enterprise applications like online transaction processing (OLTP) because of flash memory's inherent update/erasure mechanisms. In this thesis, to boost flash SSD random write performance, we develop a new cache management scheme called element-level parallel optimization (EPO), which buffers and reorders write requests so that element-level parallelism within the architecture of a flash SSD can be mostly utilized. Further, we evaluate the performance of the EPO scheme using a validated disk simulator with both synthetic benchmarks and real-world server-class traces. Experimental results demonstrate that EPO noticeably outperforms traditional least recently used (LRU) and a state-of-the-art flash write buffer management scheme block padding least recently used (BPLRU).
| Author | : Jingpei Yang |
| Publisher | : |
| Total Pages | : 137 |
| Release | : 2014 |
| Genre | : |
| ISBN | : 9781321088861 |
Download Improving Performance for Flash-based Storage Systems Book in PDF, ePub and Kindle
In the third part of this dissertation, we explore the approaches to collapsing logs. While there are several popular ways that utilize the nature of flash memory translation layer to eliminate multiple layers of logs in the entire system, we focus on the benefit we can obtain from a log-less object-based flash aware system. We show from simulation experiments that advanced features could be embedded to improve overall performance for object-based flash system with low overhead through a rich interface.
| Author | : James Park |
| Publisher | : |
| Total Pages | : 152 |
| Release | : 2014 |
| Genre | : |
| ISBN | : |
Download Managing and Exploiting Flash-based Storage for Data-intensive Systems Book in PDF, ePub and Kindle
"Modern computing has matured into a data-intensive, service-oriented activity, leading to increasing storage and I/O demands. However, current storage systems are built on slow, failure-prone, mechanical disks. These systems already face limitations of deployment scale, power consumption and performance. In order to meet current and future storage needs, systems need to incorporate new storage media. NAND Flash is steadily maturing as a mass storage device, and Flash-based storage systems are a promising solution for the new demands of data-driven computing. Flash-based storage promises better performance than mechanical disks. However, existing system software is ill-suited to properly manage the performance characteristics of Flash-based storage. The combination of inappropriate system support and Flash characteristics can lead to the breakdown of service guarantees like fairness and performance isolation. On the other hand, in developing appropriate system support for Flash-based storage, the opportunity to develop mechanisms for additional, stronger service guarantees arises. This dissertation approaches system support for Flash-based storage from two perspectives. First, understanding and managing Flash performance is necessary in order to provide reliable service to applications. In particular, an I/O scheduler based on Flash-oriented principles can provide better fairness and efficiency than traditional I/O schedulers. Second, Flash-based storage provides unique characteristics and high performance that can enable more powerful I/O capabilities that a properly designed system can provide to users. Flash-based storage can efficiently support a new I/O primitive, failure-atomic msync(), that allows application programmers to failure-atomically evolve durable application state in a straightforward manner"--Page v-vi.
| Author | : Aayush Gupta |
| Publisher | : |
| Total Pages | : 138 |
| Release | : 2012 |
| Genre | : |
| ISBN | : |
Download Towards Smarter Flash-based Storage Management for Enterprise Workloads Book in PDF, ePub and Kindle
| Author | : 石亮 |
| Publisher | : |
| Total Pages | : 226 |
| Release | : 2013 |
| Genre | : Computer storage devices |
| ISBN | : |
Download Performance Enhancement for Flash Memory Based Storage Systems Book in PDF, ePub and Kindle
| Author | : Haobo Wang |
| Publisher | : |
| Total Pages | : 114 |
| Release | : 2018 |
| Genre | : |
| ISBN | : |
Download Optimizing Flash-Based Storage Systems Book in PDF, ePub and Kindle
This dissertation proposes mathematical algorithms for improving Flash-based storage system's four key performance metrics: lifetime, reliability, latency and throughput. The first part of the dissertation presents the novel concept of dynamically voltage allocation (DVA) for Flash memory. Flash memory suffers reduced reliability as the number of program/erase (P/E) cycles increases, thus has a limited lifetime. DVA scales the write threshold voltages of Flash memory adaptively, using lower voltages at the beginning of the lifetime, and gradually increases the scaling to combat the effect of accumulated wear-out from P/E cycling. The proposed algorithm significantly increases the lifetime of the device. The second part of the dissertation introduces the novel design of error correction using incremental redundancy without feedback. Modern storage systems often require high throughput, high reliability and low latency. Traditional variable-length (VL) codes with feedback have demonstrated to provide high throughput and reliability. The new design reinterprets the results for VL codes with feedback using ergodicity, by encoding the incremental redundancy of multiple VL codewords to a common pool of redundancy. The removal of feedback allows storage systems to benefit from the performance of a feedback scheme with a feedforward design. The decoder of the new design exploits the low complexity of short-blocklength decoders and the parallelization structure to reduce latency. The proposed error correction scheme approaches the throughput of corresponding VL codes with feedback. Relying on information theory and coding theory, the proposed algorithms provide new approaches to optimize the Flash-based storage systems.
| Author | : Rino Micheloni |
| Publisher | : Springer Science & Business Media |
| Total Pages | : 391 |
| Release | : 2012-10-15 |
| Genre | : Science |
| ISBN | : 9400751451 |
Download Inside Solid State Drives (SSDs) Book in PDF, ePub and Kindle
Solid State Drives (SSDs) are gaining momentum in enterprise and client applications, replacing Hard Disk Drives (HDDs) by offering higher performance and lower power. In the enterprise, developers of data center server and storage systems have seen CPU performance growing exponentially for the past two decades, while HDD performance has improved linearly for the same period. Additionally, multi-core CPU designs and virtualization have increased randomness of storage I/Os. These trends have shifted performance bottlenecks to enterprise storage systems. Business critical applications such as online transaction processing, financial data processing and database mining are increasingly limited by storage performance. In client applications, small mobile platforms are leaving little room for batteries while demanding long life out of them. Therefore, reducing both idle and active power consumption has become critical. Additionally, client storage systems are in need of significant performance improvement as well as supporting small robust form factors. Ultimately, client systems are optimizing for best performance/power ratio as well as performance/cost ratio. SSDs promise to address both enterprise and client storage requirements by drastically improving performance while at the same time reducing power. Inside Solid State Drives walks the reader through all the main topics related to SSDs: from NAND Flash to memory controller (hardware and software), from I/O interfaces (PCIe/SAS/SATA) to reliability, from error correction codes (BCH and LDPC) to encryption, from Flash signal processing to hybrid storage. We hope you enjoy this tour inside Solid State Drives.
| Author | : Jiwu Shu |
| Publisher | : Springer Nature |
| Total Pages | : 436 |
| Release | : |
| Genre | : |
| ISBN | : 9819735343 |
Download Data Storage Architectures and Technologies Book in PDF, ePub and Kindle
| Author | : Mochan Shrestha |
| Publisher | : |
| Total Pages | : 300 |
| Release | : 2014 |
| Genre | : Computer science |
| ISBN | : |
Download Study On Endurance of Flash Memory Ssds Book in PDF, ePub and Kindle
Flash memory promises to revolutionize storage systems because of its massive performance gains, ruggedness, large decrease in power usage and physical space requirements, but it is not a direct replacement for magnetic hard disks. Flash memory possesses fundamentally different characteristics and in order to fully utilize the positive aspects of flash memory, we must engineer around its unique limitations. The primary limitations are lack of in-place updates, the asymmetry between the sizes of the write and erase operations, and the limited endurance of flash memory cells. This leads to the need for efficient methods for block cleaning, combating write amplification and performing wear leveling. These are fundamental attributes of flash memory and will always need to be understood and efficiently managed to produce an efficient and high performance storage system. Our goal in this work is to provide analysis and algorithms for efficiently managing data storage for endurance in flash memory. We present update codes, a class of floating codes, which encodes data updates as flash memory cell increments that results in reduced block erases and longer lifespan of flash memory, and provides a new algorithm for constructing optimal floating codes. We also analyze the theoretically possible limits of write amplification reduction and minimization by using offline workloads. We give an estimation of the minimal write amplification by a workload decomposition algorithm and find that write amplification can be pushed to zero with relatively low over-provisioning. Additionally, we give simple, efficient and practical algorithms that are effective in reducing write amplification and performing wear leveling. Finally, we present a quantitative model of wear levels in flash memory by constructing a difference equation that gives erase counts of a block with workload, wear leveling strategy and SSD configuration as parameters.
