On Mon, Apr 10, 2006 at 11:14:07PM +0200, Chris Maaskant wrote:
Ah i understand. This what "rsync -avptgoHq --delete-excluded" does. It only transfers files that are changed or added since the last backup, the "--delete-excluded" option deletes files that are deleted since the last backup.
There still is a difference. With rsync you get a 1:1 copy. With a backup you get much more then 1:1 With a backup you get this: backup 01: all files backup 02: differences with backup 01, keep backup 01 backup 03: all files, keep 01-02 backup 04: differences with 03, keep 01-04 backup 05: all files, delete 01+02, keep 03+04 backup 06: differnce with 05, keep 03-05 backup 07: all files, delete 03+04, keep 05+06 That way you always have (in this example) at least 2 backups of each file. The reason you do not do a full backup each time is space and time. Naturaly you can do a 2a, 2b, 2c, 2d ... e.g. each sunday-night a full backup, monday through saturday incremential backups. Always keep the backups from last week. Something wrong? Data lost? You can go back two weeks. Like I said, I can go back 2 months. For me that is plenty. Wether or not this is a space and timesaver depends on your type of data you want to backup. If you backup mostly fixed data, like /etc, it will safe much room and time. If you backup mailboxes that change frequently, a complete backup might be better suited, as they are always different. The end result could be that you do two backups. One for mostly fixed data. One for mostly variable data. houghi -- Nutze die Zeit. Sie ist das Kostbarste, was wir haben, denn es ist unwiederbringliche Lebenszeit. Leben ist aber mehr als Werk und Arbeit, und das Sein wichtiger als das Tun - Johannes Müller-Elmau