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Preface Towards the Reality of Petabit Networks
Preface Towards the Reality of Petabit Networks Yukou Mochida Member of the Board Fujitsu Laboratories Ltd. The telecommunications world is shifting drastically from voice oriented telephone networks to data oriented multimedia networks based on the Internet protocol (IP). Telecommunication carriers are positively extending their service attributes to new applications, and suppliers are changing their business areas and models, conforming to the radical market changes. The Internet, which was originally developed for correspondence among researchers, has evolved into a global communi- cations platform. Improvements in security technology are encouraging businesses to integrate the Internet into their intranets, and the eco- nomic world and basic life styles are being changed by the many new Internet-based services, for example, electronic commerce (EC), that have become available. This revolutionary change in telecommunications seems to come mainly from three motive forces. The first is the information society that has come into being with the wide and rapid deployment of person- al computers and mobile communications. The second is the worldwide deregulation and the resulting competitive telecommunications envi- ronment, which facilitates active investment in the growing market to construct huge-capacity networks for exploding traffic. The third is photonic networks based on wavelength division multiplexing (WDM) technology, which can greatly increase the communication capacity and drastically decrease the transmission cost per channel. Photonic net- works are attractive because they can also radically improve node throughput and offer transparency and flexibility while accommodating different signal formats and protocols, expandability for cost-effective gradual deployment, and high reliability, which is strongly required for a secure information society. -
Terabit Switching: a Survey of Techniques and Current Products
Computer Communications 25 (2002) 547±556 www.elsevier.com/locate/comcom Terabit switching: a survey of techniques and current products Amit Singhala,*, Raj Jainb aATOGA Systems Inc., 49026 Milmont, Fremont, CA 94538, USA bNayna Networks Inc., 481 Sycamore Dr, Milpitas, CA 95035, USA Received 8October 2001; accepted 8October 2001 Abstract This survey paper explains the issues in designing terabit routers and the solutions for them. The discussion includes multi-layer switching, route caching, label switching, and ef®cient routing table lookups. Router architecture issues including queuing and differentiated service are also discussed. A comparison of features of leading products is included. q 2002 Elsevier Science B.V. All rights reserved. Keywords: Routers; Computer Networking; High-Speed Routing; Routing Table Search Algorithms; Routing Products; Gigabit Routers; Terabit Routers 1. Introduction ties to handle all those channels. With increase in the speed of interfaces as well as the port density, next thing which In the present network infrastructure, world's communi- routers need to improve on is the internal switching capa- cation service providers are laying ®ber at very rapid rates. city. 64 wavelengths at OC-192 require over a terabit of And most of the ®ber connections are now being terminated switching capacity. Considering an example of Nexabit using DWDM. The combination of ®ber and DWDM has [2], a gigabit router with 40 Gbps switch capacity can made raw bandwidth available in abundance. It is possible support only a 4-channel OC-48DWDM connection. Four to transmit 64 wavelength at OC-192 on a ®ber these days of these will be required to support a 16-channel OC-48 and OC-768speeds will be available soon. -
How Many Bits Are in a Byte in Computer Terms
How Many Bits Are In A Byte In Computer Terms Periosteal and aluminum Dario memorizes her pigeonhole collieshangie count and nagging seductively. measurably.Auriculated and Pyromaniacal ferrous Gunter Jessie addict intersperse her glockenspiels nutritiously. glimpse rough-dries and outreddens Featured or two nibbles, gigabytes and videos, are the terms bits are in many byte computer, browse to gain comfort with a kilobyte est une unité de armazenamento de armazenamento de almacenamiento de dados digitais. Large denominations of computer memory are composed of bits, Terabyte, then a larger amount of nightmare can be accessed using an address of had given size at sensible cost of added complexity to access individual characters. The binary arithmetic with two sets render everything into one digit, in many bits are a byte computer, not used in detail. Supercomputers are its back and are in foreign languages are brainwashed into plain text. Understanding the Difference Between Bits and Bytes Lifewire. RAM, any sixteen distinct values can be represented with a nibble, I already love a Papst fan since my hybrid head amp. So in ham of transmitting or storing bits and bytes it takes times as much. Bytes and bits are the starting point hospital the computer world Find arrogant about the Base-2 and bit bytes the ASCII character set byte prefixes and binary math. Its size can vary depending on spark machine itself the computing language In most contexts a byte is futile to bits or 1 octet In 1956 this leaf was named by. Pages Bytes and Other Units of Measure Robelle. This function is used in conversion forms where we are one series two inputs. -
Archiving Online Data to Optical Disk
ARCHIVING ONLINE DATA TO OPTICAL DISK By J. L. Porter, J. L. Kiesler, and D. A. Stedfast U.S. GEOLOGICAL SURVEY Open-File Report 90-575 Reston, Virginia 1990 U.S. DEPARTMENT OF THE INTERIOR MANUEL LUJAN, JR., Secretary U.S. GEOLOGICAL SURVEY Dallas L. Peck, Director For additional information Copies of this report can be write to: purchased from: Chief, Distributed Information System U.S. Geological Survey U.S. Geological Survey Books and Open-File Reports Section Mail Stop 445 Federal Center, Bldg. 810 12201 Sunrise Valley Drive Box 25425 Reston, Virginia 22092 Denver, Colorado 80225 CONTENTS Page Abstract ............................................................. 1 Introduction ......................................................... 2 Types of optical storage ............................................... 2 Storage media costs and alternative media used for data archival. ......... 3 Comparisons of storage media ......................................... 3 Magnetic compared to optical media ............................... 3 Compact disk read-only memory compared to write-once/read many media ................................... 6 Erasable compared to write-once/read many media ................. 7 Paper and microfiche compared to optical media .................... 8 Advantages of write-once/read-many optical storage ..................... 8 Archival procedure and results ........................................ 9 Summary ........................................................... 13 References .......................................................... -
The Future of Data Storage Technologies
International Technology Research Institute World Technology (WTEC) Division WTEC Panel Report on The Future of Data Storage Technologies Sadik C. Esener (Panel Co-Chair) Mark H. Kryder (Panel Co-Chair) William D. Doyle Marvin Keshner Masud Mansuripur David A. Thompson June 1999 International Technology Research Institute R.D. Shelton, Director Geoffrey M. Holdridge, WTEC Division Director and ITRI Series Editor 4501 North Charles Street Baltimore, Maryland 21210-2699 WTEC Panel on the Future of Data Storage Technologies Sponsored by the National Science Foundation, Defense Advanced Research Projects Agency and National Institute of Standards and Technology of the United States government. Dr. Sadik C. Esener (Co-Chair) Dr. Marvin Keshner Dr. David A. Thompson Prof. of Electrical and Computer Director, Information Storage IBM Fellow Engineering & Material Sciences Laboratory Research Division Dept. of Electrical & Computer Hewlett-Packard Laboratories International Business Machines Engineering 1501 Page Mill Road Corporation University of California, San Diego Palo Alto, CA 94304-1126 Almaden Research Center 9500 Gilman Drive Mail Stop K01/802 La Jolla, CA 92093-0407 Dr. Masud Mansuripur 650 Harry Road Optical Science Center San Jose, CA 95120-6099 Dr. Mark H. Kryder (Co-Chair) University of Arizona Director, Data Storage Systems Center Tucson, AZ 85721 Carnegie Mellon University Roberts Engineering Hall, Rm. 348 Pittsburgh, PA 15213-3890 Dr. William D. Doyle Director, MINT Center University of Alabama Box 870209 Tuscaloosa, AL 35487-0209 INTERNATIONAL TECHNOLOGY RESEARCH INSTITUTE World Technology (WTEC) Division WTEC at Loyola College (previously known as the Japanese Technology Evaluation Center, JTEC) provides assessments of foreign research and development in selected technologies under a cooperative agreement with the National Science Foundation (NSF). -
3 Secondary Storage.PDF
CAPE COMPUTER SCIENCE SECONDARY STORAGE Secondary storage is needed 1. because there is a limit on the size of primary memory (due to cost) and 2. because RAM is volatile and so data needed for future use must be stored somewhere else so that it can be retrieved when necessary. Secondary storage is also used for backup and archives. When we consider secondary storage devices we must bear in mind the following characteristics of each device : Capacity Access speed Access method and portability Floppy Disk This is a 3.5 inch magnetic disk of flexible material which until recently was a standard feature on most microcomputers. Typically it stores 1.44 MB of data. It’s a thin plastic circle coated with a magnetic material and encased in a rigid plastic to protect it. A metal sliding access shuttle opens when the disk is in the machine allowing the read/write head access to the disk. Data can be written to and erased from a floppy disk. A write protect tab can be used to prevent accidental overwriting of data. Before data can be written to a disk, it must be formatted. This prepares the disk for use by creating a magnetic map on the disks surface. This map consists of tracks and sectors. Formatting also prepares the file allocation table (FAT). The address of a file on a floppy disk is comprised of the track number and the sector number. Floppy disks are direct access devices but they are slow compared to hard disks. The floppies great advantage has been its use as a device to help transport small files between machines. -
Unit 5: Memory Organizations
Memory Organizations Unit 5: Memory Organizations Introduction This unit considers the organization of a computer's memory system. The characteristics of the most important storage technologies are described in detail. Basically memories are classified as main memory and secondary memory. Main memory with many different categories are described in Lesson 1. Lesson 2 focuses the secondary memory including the details of floppy disks and hard disks. Lesson 1: Main Memory 1.1 Learning Objectives On completion of this lesson you will be able to : • describe the memory organization • distinguish between ROM, RAM, PROM, EEPROM and • other primary memory elements. 1.2 Organization Computer systems combine binary digits to form groups called words. The size of the word varies from system to system. Table 5.1 illustrates the current word sizes most commonly used with the various computer systems. Two decades ago, IBM introduced their 8-bit PC. This was Memory Organization followed a few years later by the 16-bit PC AT microcomputer, and already it has been replaced with 32- and 64-bit systems. The machine with increased word size is generally faster because it can process more bits of information in the same time span. The current trend is in the direction of the larger word size. Microcomputer main memories are generally made up of many individual chips and perform different functions. The ROM, RAM, Several types of semi- PROM, and EEPROM memories are used in connection with the conductor memories. primary memory of a microcomputers. The main memory generally store computer words as multiple of bytes; each byte consisting of eight bits. -
SŁOWNIK POLSKO-ANGIELSKI ELEKTRONIKI I INFORMATYKI V.03.2010 (C) 2010 Jerzy Kazojć - Wszelkie Prawa Zastrzeżone Słownik Zawiera 18351 Słówek
OTWARTY SŁOWNIK POLSKO-ANGIELSKI ELEKTRONIKI I INFORMATYKI V.03.2010 (c) 2010 Jerzy Kazojć - wszelkie prawa zastrzeżone Słownik zawiera 18351 słówek. Niniejszy słownik objęty jest licencją Creative Commons Uznanie autorstwa - na tych samych warunkach 3.0 Polska. Aby zobaczyć kopię niniejszej licencji przejdź na stronę http://creativecommons.org/licenses/by-sa/3.0/pl/ lub napisz do Creative Commons, 171 Second Street, Suite 300, San Francisco, California 94105, USA. Licencja UTWÓR (ZDEFINIOWANY PONIŻEJ) PODLEGA NINIEJSZEJ LICENCJI PUBLICZNEJ CREATIVE COMMONS ("CCPL" LUB "LICENCJA"). UTWÓR PODLEGA OCHRONIE PRAWA AUTORSKIEGO LUB INNYCH STOSOWNYCH PRZEPISÓW PRAWA. KORZYSTANIE Z UTWORU W SPOSÓB INNY NIŻ DOZWOLONY NA PODSTAWIE NINIEJSZEJ LICENCJI LUB PRZEPISÓW PRAWA JEST ZABRONIONE. WYKONANIE JAKIEGOKOLWIEK UPRAWNIENIA DO UTWORU OKREŚLONEGO W NINIEJSZEJ LICENCJI OZNACZA PRZYJĘCIE I ZGODĘ NA ZWIĄZANIE POSTANOWIENIAMI NINIEJSZEJ LICENCJI. 1. Definicje a."Utwór zależny" oznacza opracowanie Utworu lub Utworu i innych istniejących wcześniej utworów lub przedmiotów praw pokrewnych, z wyłączeniem materiałów stanowiących Zbiór. Dla uniknięcia wątpliwości, jeżeli Utwór jest utworem muzycznym, artystycznym wykonaniem lub fonogramem, synchronizacja Utworu w czasie z obrazem ruchomym ("synchronizacja") stanowi Utwór Zależny w rozumieniu niniejszej Licencji. b."Zbiór" oznacza zbiór, antologię, wybór lub bazę danych spełniającą cechy utworu, nawet jeżeli zawierają nie chronione materiały, o ile przyjęty w nich dobór, układ lub zestawienie ma twórczy charakter. -
High-Speed, In-Band Performance Measurement Instrumentation for Next Generation IP Networks
Pezaros, D., Georgopoulos, K. and Hutchison, D. (2010) High-speed, in- band performance measurement instrumentation for next generation IP networks. Computer Networks, 54 (18). pp. 3246-3263. ISSN 1389-1286. http://eprints.gla.ac.uk/49268/ Deposited on: 14 February 2011 Enlighten – Research publications by members of the University of Glasgow http://eprints.gla.ac.uk High-Speed, In-band Performance Measurement Instrumentation for Next Generation IP Networks Dimitrios P. Pezaros, MIEEE Konstantinos Georgopoulos David Hutchison, MIEEE Department of Computing Science Engineering Department Computing Department University of Glasgow Lancaster University Lancaster University Glasgow, UK Lancaster, UK Lancaster, UK G12 8QQ LA1 4YR LA1 4WA [email protected] [email protected] [email protected] Abstract. Facilitating always-on instrumentation of Internet traffic for the purposes of performance measurement is crucial in order to enable accountability of resource usage and automated network control, management and optimisation. This has proven infeasible to date due to the lack of native measurement mechanisms that can form an integral part of the network‟s main forwarding operation. However, Internet Protocol version 6 (IPv6) specification enables the efficient encoding and processing of optional per-packet information as a native part of the network layer, and this constitutes a strong reason for IPv6 to be adopted as the ubiquitous next generation Internet transport. In this paper we present a very high-speed hardware implementation of in-line measurement, a truly native traffic instrumentation mechanism for the next generation Internet, which facilitates performance measurement of the actual data-carrying traffic at small timescales between two points in the network. -
EE 4504 Computer Organization Overview
Overview Historically, the limiting factor in a computer’s performance has been memory access time – Memory speed has been slow compared to the speed of the processor EE 4504 – A process could be bottlenecked by the memory Computer Organization system’s inability to “keep up” with the processor Our goal in this section is to study the development of an effective memory Section 3 organization that supports the processing Computer Memory power of the CPU – General memory organization and performance – “Internal” memory components and their use – “External” memory components and their use Reading: Text, chapters 4 and 5 EE 4504 Section 3 1 EE 4504 Section 3 2 1 Terminology Capacity: the amount of information that Access time: can be contained in a memory unit -- – For RAM, the time to address the unit and usually in terms of words or bytes perform the transfer Word: the natural unit of organization in – For non-random access memory, the time to position the R/W head over the desired location the memory, typically the number of bits used to represent a number Memory cycle time: Access time plus any other time required before a second access Addressable unit: the fundamental data can be started element size that can be addressed in the memory -- typically either the word size or Access technique: how are memory individual bytes contents accessed – Random access: Unit of transfer: The number of data » Each location has a unique physical address elements transferred at a time -- usually » Locations can be accessed in any order and bits in main -
Dissertation
ADAM: A Decentralized Parallel Computer Architecture Featuring Fast Thread and Data Migration and a Uniform Hardware Abstraction by Andrew “bunnie” Huang Submitted to the Department of Electrical Engineering and Computer Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June 2002 c Massachusetts Institute of Technology 2002. All rights reserved. Author........................................................................... Department of Electrical Engineering and Computer Science May 24, 2002 Certifiedby....................................................................... Thomas F. Knight, Jr. Senior Research Scientist Thesis Supervisor Accepted by ...................................................................... Arthur C. Smith Chairman, Department Committee on Graduate Students 2 ADAM: A Decentralized Parallel Computer Architecture Featuring Fast Thread and Data Migration and a Uniform Hardware Abstraction by Andrew “bunnie” Huang Submitted to the Department of Electrical Engineering and Computer Science on May 24, 2002, in partial fulfillment of the requirements for the degree of Doctor of Philosophy Abstract The furious pace of Moore’s Law is driving computer architecture into a realm where the the speed of light is the dominant factor in system latencies. The number of clock cycles to span a chip are increasing, while the number of bits that can be accessed within a clock cycle is decreasing. Hence, it is becoming more difficult to hide latency. One alternative solution is to reduce latency by migrating threads and data, but the overhead of existing implementations has previously made migration an unserviceable solution so far. I present an architecture, implementation, and mechanisms that reduces the overhead of mi- gration to the point where migration is a viable supplement to other latency hiding mechanisms, such as multithreading. -
Memory and Storage Systems
CHAPTER 3 MEMORY AND STORAGE SYSTEMS Chapter Outline Chapter Objectives 3.1 Introduction In this chapter, we will learn: 3.2 Memory Representation ∑ The concept of memory and its 3.3 Random Access Memory representation. 3.3.1 Static RAM ∑ How data is stored in Random Access 3.3.2 Dynamic RAM Memory (RAM) and the various types of 3.4 Read Only Memory RAM. 3.4.1 Programmable ROM ∑ How data is stored in Read Only Memory 3.4.2 Erasable PROM (ROM) and the various types of ROM. 3.4.3 Electrically Erasable PROM ∑ The concept of storage systems and the 3.4.4 Flash ROM various types of storage systems. 3.5 Storage Systems ∑ The criteria for evaluating storage 3.6 Magnetic Storage Systems systems. 3.6.1 Magnetic Tapes 3.6.2 Magnetic Disks 3.7 Optical Storage Systems 3.1 INTRODUCTION 3.7.1 Read only Optical Disks 3.7.2 Write Once, Read Many Disks Computers are used not only for processing of data 3.8 Magneto Optical Systems for immediate use, but also for storing of large 3.8.1 Principle used in Recording Data volume of data for future use. In order to meet 3.8.2 Architecture of Magneto Optical Disks these two specifi c requirements, computers use two 3.9 Solid-State Storage Devices types of storage locations—one, for storing the data 3.9.1 Structure of SSD that are being currently handled by the CPU and the 3.9.2 Advantages of SSD other, for storing the results and the data for future 3.9.3 Disadvantages of SSD use.