Storage

Storage

A device capable of storing data. The term usually refers to mass storage devices, such as disk and tape drives.



Storage devices
A storage device is a hardware device designed to store information. There are two types of storage devices used in computers; a 'primary storage' device and a 'secondary storage' device.

• Hard Disk Drives

In any computer system the hard disk is considered as the secondary memory device that is used for the primary data storage. The primary memory is obviously the RAM. But as the RAM is the primary memory it cannot be used for the purpose of the permanent data storage. Hence a secondary memory device is necessarily needed for the purpose of the data storage in any computer system. Apart from hard disk drive the tape storage media can also be used as the secondary storage device. But the hard disk drive is the most popularly used secondary memory device. The main reason for this is the access speed and the reliability of the data it can offer. In the case of the tape drives the access speed is much low and the data transfer is comparatively low than the hard disk drive.

Since the primary memory that is the RAM is a non volatile memory hence it cannot be used as the permanent memory storage device. Hence the hard disk or the need for as a secondary memory device is needed in any computer. The primary function of the primary memory is to load the programs so that the CPU – Central Processing Unit can easily and speedily access and execute the instructions. The primary memory can only boot the computer system; but it the hard disk drive that is responsible for the loading and the proper functioning of any operating system. The operating system is a necessary for the computers to run to the expectations of the user. Hence the hard disk is a must for the loading of the hard disk drive. The importance of the primary memory is that it is a compulsion that is necessary for the start up of the computer. A computer can start up even with out a hard disk. But since there is no operating system that is present in the computer hence it is not possible to load the operating system. The computer will display a message usually in such a situation stating that “Disk Boot Failure”.

The information that is required to boot a computer is stored in the hard disk boot sector. Also the importance of the hard disk drive is to store the backup of the data or any information that is created by the user. Apart from the hard disk drives the other storage devices like the optical disks that are the CD ROM, DVD ROM etc can be used for the purpose of the backup of the data or user information. The floppy disks can also be used for the backup of the data. The hard disk specification should also match the expectations of the computers; that is the storage capacity and access speed.

The internal organization of the any hard disk drive consists of the following four parts primarily. They are as listed below: the Platters, the Head Arm, the Chassis, and also the Head Actuator. The hard disk drives are also available in two different types that is the internal and also the external hard disk drives. The internal hard disk drives are used for the storage of the data in the computer case. There are not portable and usually are inside the case. The external hard disk drives are portable can be connected to other computer systems as well. There is a hard casing over the hard disk.

• USB drive

A USB drive -- also known as a flash drive or keychain drive -- is a plug-and-play portable storage device that uses flash memory and is lightweight enough to attach to a key chain. A USB drive can be used in place of a floppy disk, Zip drive disk, or CD. When the user plugs the device into the USB port, the computer's operating system recognizes the device as a removable drive and assigns it a drive letter.

Unlike most removable drives, a USB drive does not require rebooting after it's attached, does not require batteries or an external power supply, and is not platform dependent. Several manufacturers offer additional features such as password protection, and downloadable drivers that allow the device to be compatible with older systems that do not have USB ports. USB drives are available in capacities ranging up to about 65 gigabytes (GB), depending on manufacturer, in a corresponding range of prices.

With a USB drive, data can be retained for long periods when the device is unplugged from the computer, or when the computer is powered-down with the drive left in. This makes the USB drive convenient for transferring data between a desktop computer and a notebook computer, or for personal backup needs.

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