Advantages Files are easily found when needed. If you should need to restore the entire system, all of the most current information can be found on the last backup tape. Disadvantages Redundant backups. Since most of the files on your system rarely change, each backup following the first is mostly a copy of what has already been backed up. Full backups take longer to perform and can be very time consuming.
Archive bit is reset.
Advantages Better use of media. Only files that were created or changed since the last backup are included, so there is much less data storage space required. Less time required, since it only backs up the files that have been modified since the last backup. Disadvantages Multiple tapes needed for restore. The files can be spread over all the tapes in use since the last full backup.