Advances in Data Storage Technology
Advances in Data Storage Technology
Contents
I. Introduction 3
II. Purpose of storage 4
III. Hierarchy of storage 6 A. Primary storage 6 B. Secondary storage 7 C. Tertiary storage 7 D. Off-line storage 8
IV. Characteristics of storage 9 A. Volatility 9 B. Mutability 9 C. Accessibility 10 D. Addressability 10 E. Capacity 11 F. Performance 11 G. Energy use 11
V. Fundamental storage technologies 12 A. Semiconductor 12 B. Magnetic 12 C. Optical 13 D. Paper 14 E. Uncommon 14
VI. Related technologies 17 A. Network connectivity 17 B. Robotic storage 17
References 19
I. INTRODUCTION
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data used for computing for some interval of time. Computer data storage provides one of the core functions of the modern computer, that of information retention. It is one of the fundamental components of all modern computers, and coupled with a central processing unit (CPU, a processor), implements the basic computer model used since the 1940s. In contemporary usage, memory usually refers to a form of semiconductor storage known as random-access memory (RAM) and sometimes other forms of fast but temporary storage. Similarly, storage today more commonly refers to mass storage — optical discs, forms of magnetic storage like hard disk drives, and other types slower than RAM, but of a more permanent nature. Historically, memory and storage were respectively called main memory and secondary storage (or auxiliary storage). Auxiliary storage (or auxiliary memory units) was also used to represent memory which was not directly accessible by the CPU (secondary or tertiary storage). The terms internal memory and external
Contents
I. Introduction 3
II. Purpose of storage 4
III. Hierarchy of storage 6 A. Primary storage 6 B. Secondary storage 7 C. Tertiary storage 7 D. Off-line storage 8
IV. Characteristics of storage 9 A. Volatility 9 B. Mutability 9 C. Accessibility 10 D. Addressability 10 E. Capacity 11 F. Performance 11 G. Energy use 11
V. Fundamental storage technologies 12 A. Semiconductor 12 B. Magnetic 12 C. Optical 13 D. Paper 14 E. Uncommon 14
VI. Related technologies 17 A. Network connectivity 17 B. Robotic storage 17
References 19
I. INTRODUCTION
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data used for computing for some interval of time. Computer data storage provides one of the core functions of the modern computer, that of information retention. It is one of the fundamental components of all modern computers, and coupled with a central processing unit (CPU, a processor), implements the basic computer model used since the 1940s. In contemporary usage, memory usually refers to a form of semiconductor storage known as random-access memory (RAM) and sometimes other forms of fast but temporary storage. Similarly, storage today more commonly refers to mass storage — optical discs, forms of magnetic storage like hard disk drives, and other types slower than RAM, but of a more permanent nature. Historically, memory and storage were respectively called main memory and secondary storage (or auxiliary storage). Auxiliary storage (or auxiliary memory units) was also used to represent memory which was not directly accessible by the CPU (secondary or tertiary storage). The terms internal memory and external
References: J. S. Vitter, Algorithms and Data Structures for External Memory. Series on Foundations and Trends in Theoretical Computer Science, now Publishers, Hanover, MA, 2008, ISBN 978-1-60198-106-6. National Communications System (1996). Federal Standard 1037C - Telecommunications: Glossary of Telecommunication Terms. Super Talent 's 2.5" IDE Flash hard drive - The Tech Report - Page 13. (http://techreport.com/articles.x/10334/13)