1.3.2 Main Memory with Majid Tahir
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Hard Disk Drives
37 Hard Disk Drives The last chapter introduced the general concept of an I/O device and showed you how the OS might interact with such a beast. In this chapter, we dive into more detail about one device in particular: the hard disk drive. These drives have been the main form of persistent data storage in computer systems for decades and much of the development of file sys- tem technology (coming soon) is predicated on their behavior. Thus, it is worth understanding the details of a disk’s operation before building the file system software that manages it. Many of these details are avail- able in excellent papers by Ruemmler and Wilkes [RW92] and Anderson, Dykes, and Riedel [ADR03]. CRUX: HOW TO STORE AND ACCESS DATA ON DISK How do modern hard-disk drives store data? What is the interface? How is the data actually laid out and accessed? How does disk schedul- ing improve performance? 37.1 The Interface Let’s start by understanding the interface to a modern disk drive. The basic interface for all modern drives is straightforward. The drive consists of a large number of sectors (512-byte blocks), each of which can be read or written. The sectors are numbered from 0 to n − 1 on a disk with n sectors. Thus, we can view the disk as an array of sectors; 0 to n − 1 is thus the address space of the drive. Multi-sector operations are possible; indeed, many file systems will read or write 4KB at a time (or more). However, when updating the disk, the only guarantee drive manufacturers make is that a single 512-byte write is atomic (i.e., it will either complete in its entirety or it won’t com- plete at all); thus, if an untimely power loss occurs, only a portion of a larger write may complete (sometimes called a torn write). -
Storage Systems and Technologies - Jai Menon and Clodoaldo Barrera
INFORMATION TECHNOLOGY AND COMMUNICATIONS RESOURCES FOR SUSTAINABLE DEVELOPMENT - Storage Systems and Technologies - Jai Menon and Clodoaldo Barrera STORAGE SYSTEMS AND TECHNOLOGIES Jai Menon IBM Academy of Technology, San Jose, CA, USA Clodoaldo Barrera IBM Systems Group, San Jose, CA, USA Keywords: Storage Systems, Hard disk drives, Tape Drives, Optical Drives, RAID, Storage Area Networks, Backup, Archive, Network Attached Storage, Copy Services, Disk Caching, Fiber Channel, Storage Switch, Storage Controllers, Disk subsystems, Information Lifecycle Management, NFS, CIFS, Storage Class Memories, Phase Change Memory, Flash Memory, SCSI, Caching, Non-Volatile Memory, Remote Copy, Storage Virtualization, Data De-duplication, File Systems, Archival Storage, Storage Software, Holographic Storage, Storage Class Memory, Long-Term data preservation Contents 1. Introduction 2. Storage devices 2.1. Storage Device Industry Overview 2.2. Hard Disk Drives 2.3. Digital Tape Drives 2.4. Optical Storage 2.5. Emerging Storage Technologies 2.5.1. Holographic Storage 2.5.2. Flash Storage 2.5.3. Storage Class Memories 3. Block Storage Systems 3.1. Storage System Functions – Current 3.2. Storage System Functions - Emerging 4. File and Archive Storage Systems 4.1. Network Attached Storage 4.2. Archive Storage Systems 5. Storage Networks 5.1. SAN Fabrics 5.2. IP FabricsUNESCO – EOLSS 5.3. Converged Networking 6. Storage SoftwareSAMPLE CHAPTERS 6.1. Data Backup 6.2. Data Archive 6.3. Information Lifecycle Management 6.4. Disaster Protection 7. Concluding Remarks Acknowledgements Glossary Bibliography Biographical Sketches ©Encyclopedia of Life Support Systems (EOLSS) INFORMATION TECHNOLOGY AND COMMUNICATIONS RESOURCES FOR SUSTAINABLE DEVELOPMENT - Storage Systems and Technologies - Jai Menon and Clodoaldo Barrera Summary Our world is increasingly becoming a data-centric world. -
Nanotechnology ? Nram (Nano Random Access
International Journal Of Engineering Research and Technology (IJERT) IFET-2014 Conference Proceedings INTERFACE ECE T14 INTRACT – INNOVATE - INSPIRE NANOTECHNOLOGY – NRAM (NANO RANDOM ACCESS MEMORY) RANJITHA. T, SANDHYA. R GOVERNMENT COLLEGE OF TECHNOLOGY, COIMBATORE 13. containing elements, nanotubes, are so small, NRAM technology will Abstract— NRAM (Nano Random Access Memory), is one of achieve very high memory densities: at least 10-100 times our current the important applications of nanotechnology. This paper has best. NRAM will operate electromechanically rather than just been prepared to cull out answers for the following crucial electrically, setting it apart from other memory technologies as a questions: nonvolatile form of memory, meaning data will be retained even What is NRAM? when the power is turned off. The creators of the technology claim it What is the need of it? has the advantages of all the best memory technologies with none of How can it be made possible? the disadvantages, setting it up to be the universal medium for What is the principle and technology involved in NRAM? memory in the future. What are the advantages and features of NRAM? The world is longing for all the things it can use within its TECHNOLOGY palm. As a result nanotechnology is taking its head in the world. Nantero's technology is based on a well-known effect in carbon Much of the electronic gadgets are reduced in size and increased nanotubes where crossed nanotubes on a flat surface can either be in efficiency by the nanotechnology. The memory storage devices touching or slightly separated in the vertical direction (normal to the are somewhat large in size due to the materials used for their substrate) due to Van der Waal's interactions. -
AXP Internal 2-Apr-20 1
2-Apr-20 AXP Internal 1 2-Apr-20 AXP Internal 2 2-Apr-20 AXP Internal 3 2-Apr-20 AXP Internal 4 2-Apr-20 AXP Internal 5 2-Apr-20 AXP Internal 6 Class 6 Subject: Computer Science Title of the Book: IT Planet Petabyte Chapter 2: Computer Memory GENERAL INSTRUCTIONS: • Exercises to be written in the book. • Assignment questions to be done in ruled sheets. • You Tube link is for the explanation of Primary and Secondary Memory. YouTube Link: ➢ https://youtu.be/aOgvgHiazQA INTRODUCTION: ➢ Computer can store a large amount of data safely in their memory for future use. ➢ A computer’s memory is measured either in Bits or Bytes. ➢ The memory of a computer is divided into two categories: Primary Memory, Secondary Memory. ➢ There are two types of Primary Memory: ROM and RAM. ➢ Cache Memory is used to store program and instructions that are frequently used. EXPLANATION: Computer Memory: Memory plays a very important role in a computer. It is the basic unit where data and instructions are stored temporarily. Memory usually consists of one or more chips on the mother board, or you can say it consists of electronic components that store instructions waiting to be executed by the processor, data needed by those instructions, and the results of processing the data. Memory Units: Computer memory is measured in bits and bytes. A bit is the smallest unit of information that a computer can process and store. A group of 4 bits is known as nibble, and a group of 8 bits is called byte. -
Nasdeluxe Z-Series
NASdeluxe Z-Series Benefit from scalable ZFS data storage By partnering with Starline and with Starline Computer’s NASdeluxe Open-E, you receive highly efficient Z-series and Open-E JovianDSS. This and reliable storage solutions that software-defined storage solution is offer: Enhanced Storage Performance well-suited for a wide range of applica- tions. It caters perfectly to the needs • Great adaptability Tiered RAM and SSD cache of enterprises that are looking to de- • Tiered and all-flash storage Data integrity check ploy a flexible storage configuration systems which can be expanded to a high avail- Data compression and in-line • High IOPS through RAM and SSD ability cluster. Starline and Open-E can data deduplication caching look back on a strategic partnership of Thin provisioning and unlimited • Superb expandability with more than 10 years. As the first part- number of snapshots and clones ner with a Gold partnership level, Star- Starline’s high-density JBODs – line has always been working hand in without downtime Simplified management hand with Open-E to develop and de- Flexible scalability liver innovative data storage solutions. Starline’s NASdeluxe Z-Series offers In fact, Starline supports worldwide not only great features, but also great Hardware independence enterprises in managing and pro- flexibility – thanks to its modular archi- tecting their storage, with over 2,800 tecture. Open-E installations to date. www.starline.de Z-Series But even with a standard configuration with nearline HDDs IOPS and SSDs for caching, you will be able to achieve high IOPS 250 000 at a reasonable cost. -
Use External Storage Devices Like Pen Drives, Cds, and Dvds
External Intel® Learn Easy Steps Activity Card Storage Devices Using external storage devices like Pen Drives, CDs, and DVDs loading Videos Since the advent of computers, there has been a need to transfer data between devices and/or store them permanently. You may want to look at a file that you have created or an image that you have taken today one year later. For this it has to be stored somewhere securely. Similarly, you may want to give a document you have created or a digital picture you have taken to someone you know. There are many ways of doing this – online and offline. While online data transfer or storage requires the use of Internet, offline storage can be managed with minimum resources. The only requirement in this case would be a storage device. Earlier data storage devices used to mainly be Floppy drives which had a small storage space. However, with the development of computer technology, we today have pen drives, CD/DVD devices and other removable media to store and transfer data. With these, you store/save/copy files and folders containing data, pictures, videos, audio, etc. from your computer and even transfer them to another computer. They are called secondary storage devices. To access the data stored in these devices, you have to attach them to a computer and access the stored data. Some of the examples of external storage devices are- Pen drives, CDs, and DVDs. Introduction to Pen Drive/CD/DVD A pen drive is a small self-powered drive that connects to a computer directly through a USB port. -
Nanotechnology Trends in Nonvolatile Memory Devices
IBM Research Nanotechnology Trends in Nonvolatile Memory Devices Gian-Luca Bona [email protected] IBM Research, Almaden Research Center © 2008 IBM Corporation IBM Research The Elusive Universal Memory © 2008 IBM Corporation IBM Research Incumbent Semiconductor Memories SRAM Cost NOR FLASH DRAM NAND FLASH Attributes for universal memories: –Highest performance –Lowest active and standby power –Unlimited Read/Write endurance –Non-Volatility –Compatible to existing technologies –Continuously scalable –Lowest cost per bit Performance © 2008 IBM Corporation IBM Research Incumbent Semiconductor Memories SRAM Cost NOR FLASH DRAM NAND FLASH m+1 SLm SLm-1 WLn-1 WLn WLn+1 A new class of universal storage device : – a fast solid-state, nonvolatile RAM – enables compact, robust storage systems with solid state reliability and significantly improved cost- performance Performance © 2008 IBM Corporation IBM Research Non-volatile, universal semiconductor memory SL m+1 SL m SL m-1 WL n-1 WL n WL n+1 Everyone is looking for a dense (cheap) crosspoint memory. It is relatively easy to identify materials that show bistable hysteretic behavior (easily distinguishable, stable on/off states). IBM © 2006 IBM Corporation IBM Research The Memory Landscape © 2008 IBM Corporation IBM Research IBM Research Histogram of Memory Papers Papers presented at Symposium on VLSI Technology and IEDM; Ref.: G. Burr et al., IBM Journal of R&D, Vol.52, No.4/5, July 2008 © 2008 IBM Corporation IBM Research IBM Research Emerging Memory Technologies Memory technology remains an -
Control Design and Implementation of Hard Disk Drive Servos by Jianbin
Control Design and Implementation of Hard Disk Drive Servos by Jianbin Nie A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering-Mechanical Engineering in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Roberto Horowitz, Chair Professor Masayoshi Tomizuka Professor David Brillinger Spring 2011 Control Design and Implementation of Hard Disk Drive Servos ⃝c 2011 by Jianbin Nie 1 Abstract Control Design and Implementation of Hard Disk Drive Servos by Jianbin Nie Doctor of Philosophy in Engineering-Mechanical Engineering University of California, Berkeley Professor Roberto Horowitz, Chair In this dissertation, the design of servo control algorithms is investigated to produce high-density and cost-effective hard disk drives (HDDs). In order to sustain the continuing increase of HDD data storage density, dual-stage actuator servo systems using a secondary micro-actuator have been developed to improve the precision of read/write head positioning control by increasing their servo bandwidth. In this dissertation, the modeling and control design of dual-stage track-following servos are considered. Specifically, two track-following control algorithms for dual-stage HDDs are developed. The designed controllers were implemented and evaluated on a disk drive with a PZT-actuated suspension-based dual-stage servo system. Usually, the feedback position error signal (PES) in HDDs is sampled on some spec- ified servo sectors with an equidistant sampling interval, which implies that HDD servo systems with a regular sampling rate can be modeled as linear time-invariant (LTI) systems. However, sampling intervals for HDD servo systems are not always equidistant and, sometimes, an irregular sampling rate due to missing PES sampling data is unavoidable. -
Parallel Computer Architecture and Programming CMU / 清华 大学
Lecture 20: Addressing the Memory Wall Parallel Computer Architecture and Programming CMU / 清华⼤学, Summer 2017 CMU / 清华⼤学, Summer 2017 Today’s topic: moving data is costly! Data movement limits performance Data movement has high energy cost Many processors in a parallel computer means… ~ 0.9 pJ for a 32-bit foating-point math op * - higher overall rate of memory requests ~ 5 pJ for a local SRAM (on chip) data access - need for more memory bandwidth to avoid ~ 640 pJ to load 32 bits from LPDDR memory being bandwidth bound Core Core Memory bus Memory Core Core CPU * Source: [Han, ICLR 2016], 45 nm CMOS assumption CMU / 清华⼤学, Summer 2017 Well written programs exploit locality to avoid redundant data transfers between CPU and memory (Key idea: place frequently accessed data in caches/buffers near processor) Core L1 Core L1 L2 Memory Core L1 Core L1 ▪ Modern processors have high-bandwidth (and low latency) access to on-chip local storage - Computations featuring data access locality can reuse data in this storage ▪ Common software optimization technique: reorder computation so that cached data is accessed many times before it is evicted (“blocking”, “loop fusion”, etc.) ▪ Performance-aware programmers go to great effort to improve the cache locality of programs - What are good examples from this class? CMU / 清华⼤学, Summer 2017 Example 1: restructuring loops for locality Program 1 void add(int n, float* A, float* B, float* C) { for (int i=0; i<n; i++) Two loads, one store per math op C[i] = A[i] + B[i]; } (arithmetic intensity = 1/3) void mul(int -
Can We Store the Whole World's Data in DNA Storage?
Can We Store the Whole World’s Data in DNA Storage? Bingzhe Li†, Nae Young Song†, Li Ou‡, and David H.C. Du† †Department of Computer Science and Engineering, University of Minnesota, Twin Cities ‡Department of Pediatrics, University of Minnesota, Twin Cities {lixx1743, song0455, ouxxx045, du}@umn.edu, Abstract DNA storage can achieve a theoretical density of 455 EB/g [9] and has a long-lasting property of several centuries [10,11]. The total amount of data in the world has been increasing These characteristics of DNA storage make it a great candi- rapidly. However, the increase of data storage capacity is date for archival storage. Many research studies focused on much slower than that of data generation. How to store and several research directions including encoding/decoding asso- archive such a huge amount of data becomes critical and ciated with error correction schemes [11–18], DNA storage challenging. Synthetic Deoxyribonucleic Acid (DNA) storage systems with microfluidic platforms [19–21], and applications is one of the promising candidates with high density and long- such as database on top of DNA storage [9]. Moreover, sev- term preservation for archival storage systems. The existing eral survey papers [22,23] on DNA storage mainly focused works have focused on the achievable feasibility of a small on the technology reviews of how to store data in DNA (in amount of data when using DNA as storage. In this paper, vivo or in vitro) including the encoding/decoding and synthe- we investigate the scalability and potentials of DNA storage sis/sequencing processes. In fact, the major focus of these when a huge amount of data, like all available data from the studies was to demonstrate the feasibility of DNA storage world, is to be stored. -
Manufacturing Equipment Technologies for Hard Disk's
Manufacturing Equipment Technologies for Hard Disk’s Challenge of Physical Limits 222 Manufacturing Equipment Technologies for Hard Disk’s Challenge of Physical Limits Kyoichi Mori OVERVIEW: To meet the world’s growing demands for volume information, Brian Rattray not just with computers but digitalization and video etc. the HDD must Yuichi Matsui, Dr. Eng. continually increase its capacity and meet expectations for reduced power consumption and green IT. Up until now the HDD has undergone many innovative technological developments to achieve higher recording densities. To continue this increase, innovative new technology is again required and is currently being developed at a brisk pace. The key components for areal density improvements, the disk and head, require high levels of performance and reliability from production and inspection equipment for efficient manufacturing and stable quality assurance. To meet this demand, high frequency electronics, servo positioning and optical inspection technology is being developed and equipment provided. Hitachi High-Technologies Corporation is doing its part to meet market needs for increased production and the adoption of next-generation technology by developing the technology and providing disk and head manufacturing/inspection equipment (see Fig. 1). INTRODUCTION higher efficiency storage, namely higher density HDDS (hard disk drives) have long relied on the HDDs will play a major role. computer market for growth but in recent years To increase density, the performance and quality of there has been a shift towards cloud computing and the HDD’s key components, disks (media) and heads consumer electronics etc. along with a rapid expansion have most effect. Therefore further technological of data storage applications (see Fig. -
The Future of DNA Data Storage the Future of DNA Data Storage
The Future of DNA Data Storage The Future of DNA Data Storage September 2018 A POTOMAC INSTITUTE FOR POLICY STUDIES REPORT AC INST M IT O U T B T The Future O E P F O G S R IE of DNA P D O U Data LICY ST Storage September 2018 NOTICE: This report is a product of the Potomac Institute for Policy Studies. The conclusions of this report are our own, and do not necessarily represent the views of our sponsors or participants. Many thanks to the Potomac Institute staff and experts who reviewed and provided comments on this report. © 2018 Potomac Institute for Policy Studies Cover image: Alex Taliesen POTOMAC INSTITUTE FOR POLICY STUDIES 901 North Stuart St., Suite 1200 | Arlington, VA 22203 | 703-525-0770 | www.potomacinstitute.org CONTENTS EXECUTIVE SUMMARY 4 Findings 5 BACKGROUND 7 Data Storage Crisis 7 DNA as a Data Storage Medium 9 Advantages 10 History 11 CURRENT STATE OF DNA DATA STORAGE 13 Technology of DNA Data Storage 13 Writing Data to DNA 13 Reading Data from DNA 18 Key Players in DNA Data Storage 20 Academia 20 Research Consortium 21 Industry 21 Start-ups 21 Government 22 FORECAST OF DNA DATA STORAGE 23 DNA Synthesis Cost Forecast 23 Forecast for DNA Data Storage Tech Advancement 28 Increasing Data Storage Density in DNA 29 Advanced Coding Schemes 29 DNA Sequencing Methods 30 DNA Data Retrieval 31 CONCLUSIONS 32 ENDNOTES 33 Executive Summary The demand for digital data storage is currently has been developed to support applications in outpacing the world’s storage capabilities, and the life sciences industry and not for data storage the gap is widening as the amount of digital purposes.