Mass storage

Mass storage

In computing, mass storage refers to the storage of large amounts of data in a persisting and machine-readable fashion. Devices and/or systems that have been described as mass storage include tape libraries, RAID systems, hard disk drives, magnetic tape drives, optical disc drives, magneto-optical disc drives, drum memory (historic), floppy disk drives (historic), punched tape (historic) and holographic memory (experimental). Mass storage includes devices with removable and non-removable media. It does not include random access memory (RAM), which is volatile in that it loses its contents after power loss.

The notion of "large" amounts of data is of course highly dependent on the time frame and the market segment, as mass storage device capacity has increased by many orders of magnitude since the beginnings of computer technology in the late 1940s and continues to grow; however, in any time frame, common mass storage devices have tended to be much larger and at the same time much slower than common realizations of the contemporaneous primary storage technology. The term mass storage was used in the PC marketplace for devices far smaller than devices that were not considered mass storage in the mainframe marketplace.

Mass storage devices are characterized by:

  • Sustainable transfer speed
  • Seek time
  • Cost
  • Capacity

Today, magnetic disks are the predominant storage media in personal computers. Optical discs, however, are almost exclusively used in the large-scale distribution of retail software, music and movies because of the cost and manufacturing efficiency of the molding process used to produce DVD and compact discs and the nearly-universal presence of reader drives in personal computers and consumer appliances.[1] Flash memory (in particular, NAND flash) has an established and growing niche as a replacement for magnetic hard disks in high performance enterprise computing installations because it has no moving parts (making it more robust) and has a much lower latency; as removable storage such as USB sticks, because in lower capacity ranges it can be made smaller and cheaper than hard disks; and on portable devices such as notebook computers and cell phones because of its lower size and weight, better tolerance of physical stress caused by e.g. shaking or dropping, and low power consumption.[2][3]

The design of computer architectures and operating systems are often dictated by the mass storage and bus technology of their time.[4] Desktop operating systems such as Windows are now so closely tied to the performance characteristics of magnetic disks that it is difficult to deploy them on other media like flash memory without running into space constraints, suffering serious performance problems or breaking applications.

Usage

Mass storage devices used in desktop and most server computers typically have their data organized in a file system. The choice of file system is often important in maximizing the performance of the device: general purpose file systems (such as NTFS and HFS, for example) tend to do poorly on slow-seeking optical storage such as compact discs.

Some relational databases can also be deployed on mass storage devices without an intermediate file system or storage manager. Oracle and MySQL, for example, can store table data directly on raw block devices.

On removable media, archive formats (such as tar archives on magnetic tape, which pack file data end-to-end) are sometimes used instead of file systems because they are more portable and simpler to stream.

On embedded computers, it is common to memory map the contents of a mass storage device (usually ROM or flash memory) so that its contents can be traversed as in-memory data structures or executed directly by programs.

References

  1. ^ Taylor, Jim. "DVD FAQ". http://www.dvddemystified.com/dvdfaq.html#1.1. Retrieved 2007-07-08. "In 2003, six years after introduction, there were over 250 million DVD playback devices worldwide, counting DVD players, DVD PCs, and DVD game consoles." 
  2. ^ Gonsalves, Antone (23 May 2007). "Micron predicts flash memory will replace disk drives". EETimes. http://www.eetimes.com/news/semi/showArticle.jhtml?articleID=199701290 .
  3. ^ "Flash Drives: Always on the Go, Without Moving Parts". New York Times. 2005-02-17. http://www.nytimes.com/2005/02/17/technology/circuits/17howw.html. Retrieved 2008-02-24. .
  4. ^ Patterson, Dave (June 2003). "A Conversation With Jim Gray" ([dead link]Scholar search). ACM Queue 1 (4). http://www.acmqueue.org/modules.php?name=Content&pa=printer_friendly&pid=43&page=1 . (A discussion of recent trents in mass storage.)

See also


Wikimedia Foundation. 2010.

Игры ⚽ Нужна курсовая?

Look at other dictionaries:

  • mass storage — noun Any form of persistent data storage technology with high capacity relative to that of the high speed non persistent memory of computers of its time. The mass storage of the network consisted of 40 megabytes of Bernoulli boxes …   Wiktionary

  • Mass Storage Control Protocol — The Mass Storage Control Protocol (MSCP) was a protocol designed by Digital Equipment Corporation of Maynard, Massachusetts for the purposes of controlling their high end mass storage options. First implemented in the HSC50 hierarchical storage… …   Wikipedia

  • Mass Storage Subsystem — Das IBM 3850 Mass Storage Subsystem war ein Massenspeichersubsystem der Firma IBM. Es war ein Vorläufer der heutigen Bandbibliotheken und ermöglichte es, Daten auf virtuellen Plattenspeichern zu verwalten. Inhaltsverzeichnis 1 Aufbau und… …   Deutsch Wikipedia

  • USB mass storage device class — The USB mass storage device class or USB MSC or UMS is a set of computing communications protocols defined by the USB Implementers Forum that run on the Universal Serial Bus. The standard provides an interface to a variety of storage devices.Some …   Wikipedia

  • USB mass storage device class — (USB MSC) (clase de dispositivo de almacenamiento masivo USB) es un conjunto de protocolos de comunicación definido por la USB Implementers Forum que funciona sobre USB. El estándar proporciona una interfaz para una variedad de dispositivos de… …   Wikipedia Español

  • USB Mass Storage — L USB Mass Storage, UMS ou USB MSC, est un protocole utilisé pour permettre à un ordinateur de communiquer avec une grande variété d appareils électroniques comme des appareils photos numériques, des clefs USB, ou des baladeurs, via un bus USB.… …   Wikipédia en Français

  • removable mass storage — standard for storage of large amounts of information which may be removed and replaced …   English contemporary dictionary

  • Mass wasting — at Palo Duro Canyon, West Texas (2002) …   Wikipedia

  • Mass spectrometry data format — Mass spectrometry is a scientific technique for measuring the mass of ions. It is often coupled to chromatographic techniques such as gas or liquid chromatography and has found widespread adoption in the fields of analytical chemistry and… …   Wikipedia

  • Storage ring — The 216 m circumference storage ring dominates this image of the interior of the Australian Synchrotron facility. In the middle of the storage ring is the booster ring and linac A storage ring is a type of circular particle accelerator in… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”