Mass storage
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- This article describes mass storage in general. For the USB protocol, see USB mass storage device class.
In computing, mass storage refers to storage of large amounts of information in a persisting and machine-readable fashion. Storage media for mass storage include hard disks, floppy disks, flash memory, optical discs, magneto-optical discs, magnetic tape, punched tape (historic) and holographic memory (experimental). It does not include random access memory, which is volatile i.e. it loses its contents after power loss.
A drive is a peripheral device attached to a computer to access the information stored on a mass storage medium. In some types of drive, the storage medium is permanently sealed inside the device. In others, the medium can be replaced with varying levels of difficulty. Also, some drives with permanently attached media are designed to be portable as a whole.
Mass storage devices are characterized by:
- Transfer speed
- Seek time
- Cost
- Capacity
Today, magnetic disks lead on all four and have come to be the dominant mass storage medium.
The design of computer architectures and operating systems are often dictated by the mass storage and bus technology of their time. 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.
References
- Patterson, Dave (2003). "A Conversation With Jim Gray". ACM Queue. (A discussion of recent trends in mass storage.)