what is meant by backup of data? Why is it necessary to make a backup or copy of your data?
Backup of Data
The copy of data or information stored in the computer hard disk or on another storage media, for example, floppy disk. Zip disk or CD- ROM is called the backup of data.The hard disk of the computer is usually used for storage of data. It is generally a reliable storage device. But it can develop problems due to voltage fluctuations or other reasons. If a hard disk is damaged, all data on it cannot be retrieved. Thus the data may be lost. In such a situation, the data stored as backup can be retrieved and stored on the new hard disk. This can save the time and the effort of creating data anew.The computer on which data is kept may be stolen or a fire in the room may damage it. In these circumstances, the backup of the data is used.It is necessary that the backup of the data be prepared regularly and placed at a fire proof and Safe-place.In large organizations, the backup of data is kept in a central network computer. In small organizations, the backup is normally kept on the floppy disks or Zip disks or Write-able CD-ROMS.There are two manners in which backups are created. These are complete backups and incremental backups.
A complete backup means a backup of all data stored on the computer hard disk.
Advantage of Complete Backup
A copy of the entire hard disk is created. The entire data can be restored if it is damaged.
Disadvantage of Complete Backup
It takes much time to create backup of entire hard disk. Each time backup is created, the entire data is copied. It takes longer time to create the backup.
An incremental Backup means the weekly backup of the entire data. At the end of the day, backup of only new files and those files that are changed since last backup, is made. It takes less time to make backup since a backup of only a small number of flies is created each day.