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.

Abstract: As an emerging storage technology, Flash Memory based Solid State Drive (SSD) has shown a high potential to fundamentally change the existing Hard Disk Drive (HDD) based storage systems. Unlike conventional magnetic disks, SSD is built on semiconductor chips and has no mechanical components (e.g. rotating disk platters). This architectural difference brings many attractive technical features, such as high random data access performance and low power consumption. Most importantly, these unique features could potentially address the long-existing technical limitations of conventional magnetic disks. Due to this reason, SSD has been called a 'pivotal technology' that may completely revolutionize current computer storage systems.

In this multicloud and cognitive era, information continues to grow rapidly. By 2025, IDC says worldwide data will grow by 61% to 175 zettabytes, with as much of the data in data centers as in the cloud. IT environments with Oracle deployments will need to accommodate that data growth, including storing, copying, mirroring, and protecting the data. When IT budgets are constrained but data keeps growing, storage costs can consume more than their fair share of the IT budget. The leading-edge portfolio of storage solutions and essential technologies of IBM® can help organizations stay ahead of the information explosion. Designed with built-in efficiency, these solutions represent preferred practices that address the following main storage objectives for hybrid multicloud environments: Stop storing so much Store more with what you have. Move Oracle and related data to balance performance and efficiency IBM offers true enterprise class storage support for Oracle deployments at a low total cost of ownership (TCO). With flash disk, tape, storage network hardware, consolidated management console, software-defined storage solutions, and security software, IBM can provide Oracle customers the full spectrum of products to meet their availability, retention, security, and compliance requirements.

4 zettabytes (4 billion terabytes) of data generated in 2013, 44 zettabytes predicted for 2020 and 185 zettabytes for 2025. These figures are staggering and perfectly illustrate this new era of data deluge. Data has become a major economic and social challenge. The speed of processing of these data is the weakest link in a computer system: the storage system. It is therefore crucial to optimize this operation. During the last decade, storage systems have experienced a major revolution: the advent of flash memory. Flash Memory Integration: Performance and Energy Issues contributes to a better understanding of these revolutions. The authors offer us an insight into the integration of flash memory in computer systems, their behavior in performance and in power consumption compared to traditional storage systems. The book also presents, in their entirety, various methods for measuring the performance and energy consumption of storage systems for embedded as well as desktop/server computer systems. We are invited on a journey to the memories of the future. - Ideal for computer scientists, featuring low level details to concentrate on system issues - Tackles flash memory aspects while spanning domains such as embedded systems and HPC - Contains an exhaustive set of experimental results conducted in the Lab-STICC laboratory - Provides details on methodologies to perform performance and energy measurements on flash storage systems

Learn deployment and configuration of Unity Storage DESCRIPTION Dell EMC Unity is a powerful midrange storage array with high-performance and deployment flexibility; it is available in the Hybrid model and All-Flash model. This solution is recommended for a mixed workload environment, remote office, and small-sized deployment. Unity systems are designed to have simple and easy implementation, configuration, and administration. Ê In this book, the reader will get an overview of Dell EMC Unity Hybrid and All-Flash storage. This book includes seven chapters, wherein you will learn the hardware installation of Unity storage and UnityVSA deployment, storage provisioning, data protection, and data replication across two Unity systems. The reader will also learn how to migrate Block data to Dell EMC Unity storage from the source storage using a data migration methodology. KEY FEATURES _Ê Overview of Dell EMC Unity Hybrid and All-Flash storage _Ê Deployment of Dell EMC Unity storage and UnityVSA _Ê Management of Dell EMC Unity storage _Ê Data protection on EMC Unity storage _Ê Data replication across EMC Unity storage _Ê Data Migration across EMC Unity storage Ê WHAT WILL YOU LEARN By the end of the book, you will have knowledge of various features of Dell EMC Unity storage, e.g., deployment, storage provisioning, and data protection and replication. Finally, you will learn a different migration methodology to migrate data to Unity storage from the source storage. Ê WHO THIS BOOK IS FOR The book is intended for anyone wanting to learn the plan and design of Dell EMC Unity storage. Storage administrators and architects, in particular, can learn about storage provisioning, data protection, and data migration in this book. Ê Table of Contents 1. Ê Ê Dell EMC Unity Overview 2. Ê Ê Dell EMC Unity Installation 3. Ê Ê Dell EMC Unity Administration and Management 4. Ê Ê Dell EMC Unity Data Protection 5. Ê Ê Dell EMC Unity Replication 6. Ê Ê Host Connectivity of Dell EMC Unity 7. Ê Ê Data Migration to Dell EMC Unity

Second, we jointly optimize the NAND flash memory's lifetime and performance with the integration of NVMs. Novel NVMs (non-volatile memories), such as PCM (Phase Change Memory) and STT-RAM (Spin-TransferTorque Random Access Memory), can provide fast read/write operations. In this thesis, we propose a unified NVM/flash architecture to improve the I/O performance. A transparent scheme, vFlash (Virtualized Flash), is also proposed to manage the unified architecture. Within vFlash, inter-app and intra-app techniques are proposed to optimize the application performance by exploiting the historical locality and I/O access patterns of applications. Since vFlash is on the bottom of the I/O stack, the application features willbe lost. Therefore, we also propose a cross-layer technique to transfer the application information from the application layer to the vFlash layer. The proposed scheme is evaluated based on an Android platform, and the experimental results show that the proposed scheme can effectively improve the I/O performance of mobile devices. Third, we study the problem of performance and lifetime enhancement in the mobile virtualization environment. Mobile virtualization introduces extra layers in software stacks, which leads to performance degradation. Especially, each I/O operation has to pass through several software layers to reach the NAND-flash-based storage systems. This thesis targets at optimizing I/O for mobile virtualization, since I/O becomes one of major performance bottlenecks that seriously affects the performance of mobile devices. Among all the I/O operations, a large percentage is updating metadata. Frequent updating metadata not only degrades overall I/O performance but also severely reduces flash memory lifetime. In this thesis, we propose a novel I/O optimization technique to identify the metadata of a guest file system which is stored in a VM (Virtual Machine) image file and frequently updated. Then, these metadata are stored in a small additional NVM (Non-Volatile Memory) which is faster and more endurable to greatly improve flash memory's performance and lifetime. To the best of our knowledge, this is the first work to identify the file system metadata from regular data in a guest OS VM image file under mobile virtualization. The proposed scheme is evaluated on a real hardware embedded platform. The experimental results show that the proposed techniques can improve write performance to 45.21% in mobile devices with virtualization.

Embedded computing systems play an important and complex role in the functionality of electronic devices. With our daily routines becoming more reliant on electronics for personal and professional use, the understanding of these computing systems is crucial. Embedded Computing Systems: Applications, Optimization, and Advanced Design brings together theoretical and technical concepts of intelligent embedded control systems and their use in hardware and software architectures. By highlighting formal modeling, execution models, and optimal implementations, this reference source is essential for experts, researchers, and technical supporters in the industry and academia.