Saturday, 17 September 2016

MAGNETIC TAPE

        Magnetic tape is a nonvolatile just like a disks storage (nonvolatile means that data is not erased from the system when system is turn off). In magnetic tape it is necessary to go through all the data before to reach a specific piece of data that is required. Magnetic tape does not provide a direct access facility for this reason magnetic tape is not suitable for database processing but magnetic tape is mostly used for backup and for storing archival data (the later used data).
For storing a large volume of data the most suitable storage media is magnetic tape, magnetic tape is a cheap and reliable medium for this purpose. The magnetic tape at a very low cost stored a hundred of millions of characters. Some reel holds an 2400 feet of tape and some tape libraries holds a thousand of reels of a tape.
Latest backup tape is used to recreate the database in the case of database disk copy is destroyed. Magnetic tape provides the facility to move data from one place to another place (from one organization to another). The composition of magnetic tape is very simple it is a plastic ribbon with an easily magnetized coating on one side of the disk. The coating material is made of iron oxide or chromium dioxide. The magnetic tape is divided into horizontal and vertical partition. The partition is called a channels (tracks) and frames. Horizontal partition in to a row is called channels or tracks. The vertical partition in to a column is called a frame. The tape drive is needed to load a tape. The tape drive is a device which has a read/write head for each track when tape passes under the heads then entire frame is read automatically. The first few feet at the start for the threading of the tape on the tape drive and last few feet at the end of the tape are left blank.                        
The load point symbol shows the start of the recording on the tape and end-of-reel symbol indicate the last recording on the tape.  Data records on the same tape may be the fixed-length-records or can be the variable-length-records. Inter-record gapes is used to separate the records on the tape. The Inter-records gapes in reality is a blank space between records. The issue of blank spaces is that they slow down the processing of a file because wasting a lot of spaces between many short records. To resolve this issue usually blocks are formed by combining a short record together. These blocks save the spaces that are wasted for separating records from each other on the disks. The numbers of bits per inch of tape determine the data density.

2 comments:

  1. Magnetic tape will be utilized in many alternative ways in which around your home, work or college. On the front of them there's associate degree adhesive face and on the rear a magnetic face, that means that you just will stick the magnet to variety of surfaces. It is thin, flexible, versatile and reasonable, that makes it helpful for variety of applications magnet tape.

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  2. A mechanism may be a terribly reliable technique of recording and archiving knowledge. employing a mag tape cartridge, the mechanism scans all of your computer's files and copies them onto the tape. Businesses would possibly like better to backup files daily, weekly, or monthly. the method is came upon to be manually run or to mechanically update at an explicit time of the day magnet tape
    .

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