File Backup
Backing up a file is saving a copy of the file on backing storage (eg disc or tape).

It is necessary to do this in case the file becomes corrupted or lost. If a file becomes unusable, the backup copy of the file may then be used. Any changes to the file since the last time the file was backed up will need to be done again.

 

Backups of a company's files can take a long time to do and so are often done at off-peak times eg at night
Important files or files that are changed often may need to be frequently backed up. 

 

Sometimes a number of backups are made and stored in different places...eg different discs stored in different rooms or buildings.
If backups are made of large files then they may be compressed before being saved. 

 

A typical scenario....

All the files used by a business are saved onto tape every night using a tape streamer. A different tape is used each night of the week ... but are then re-used the following week.

 

Exercise :
Important files need to be backed up onto a backing storage media (eg ). If a file is lost or damaged, the backup copy of the file can then be used, but all changes made to it since the last backup will need to be .

 

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