incremental backup


incremental backup

(operating system)A kind of backup that copies all fileswhich have changed since the date of the previous backup. Thefirst backup of a file system should include all files - a"full backup". Call this level 0. The next backup couldalso be a full level 0 backup but it is usually much quickerto do a level 1 backup which will include only those fileswhich have changed since the level 0 backup. Together thelevel 0 and level 1 backups will include the latest version ofevery file. Level 1 backups can be made until, say, thebackup tape is nearly full, after which we can switch to level2. Each level includes those files which have changed sincethe last backup at a lower level. The more levels you use,the longer it will take to restore the latest version of afile (or all files) if you don't know when it was lastmodified.

Compare differential backup.