Incremental Backup

Incremental Backup

Incremental backups include files that were created or changed since the last backup (that is, the last full or incremental backup).

To achieve this, the status of each file must be recorded either within the backup software or through the use of the archive attribute of the files. If no previous backup was made, an incremental backup is equivalent to a full backup.

Incremental backups make better use of media compared to full backups. Only files that were created or changed since the last backup are included, so less backup space is used and less time is required.

The disadvantage is that multiple tapes are needed to restore a set of files. The files can be spread over all the tapes in use since the last full backup. You may have to search several tapes to find the file you wish to restore. The backup software can minimize this by remembering where files are located; however a restoration may still require access to all incremental backups.