Full Backup
The preferred method of backup is the full backup method, which copies all files and directories from the hard disk to the backup media. There are a few reasons why doing a full backup is not always possible. First among them is likely the time involved in performing a full backup.
Depending on the amount of data to be backed up, full backups can take an extremely long time and can use extensive system resources. Depending on the configuration of the backup hardware, this can slow down the network considerably. In addition, some environments have more data than can fit on a single tape. This makes taking a full backup awkward, as someone may need to be there to manually change the tapes.
The main advantage of full backups is that a single tape or tape set holds all the data you need backed up. In the event of a failure, a single tape might be all that is needed to get all data and system information back. The upshot of all this is that any disruption to the network is greatly reduced.
Unfortunately, its strength can also be its weakness. A single tape holding an organization's data can be a security risk. If the tape were to fall into the wrong hands, all the data can be restored on another computer. Using passwords on tape backups and using a secure offsite and onsite location can minimize the security risk.