Sounds like you're doing small-scale backups to me
If you want large scale, this typically means tape, either single drives for smaller data sets:
Or autoloaders all the way up to libraries for larger solutions:
) or the corresponding corporate site Zmanda (http://www.zmanda.com/
) are very popular applications for operating your tape backup system. And there's plenty of other closed source ones too.
If you just want incremental backups to disk, you can use Amanda and run it to disk rather than to tape.
It all depends on what your needs are.