Then you are probably the sort that wants to use rsync and the --link-dest option, which is about the same. (Except for the nice retrieval interface.) You can

Then you are probably the sort that wants to use rsync and the --link-dest option, which is about the same. (Except for the nice retrieval interface.) You can make a new backup and it will only consume space and copy bandwidth for the files which have changed. It is cheap to keep N backups for large N.