different options, same result?

[Syzygies]

I'm pretty good about not deleting files that I want, it's usually an older version of an existing file that I go hunting down. So Copy Different is backwards from what I want. I'd like to save everything, but I most want to save old versions of files that continue to exist.

Similar programs such as duplicate hunters offer an alternative to moving files to the trash. Could SD! do this?

Let me handle the rest, e.g. moving old archive folders to DVD before the archive drive fills up. Spotlight is a reasonable tool for searching such folders, and one knows they'll remain accessible decades into the future, unlike proprietary backup formats. In comparison, with proprietary backup formats like Retrospect uses, I'm always discarding old archives to free the media. I can't easily factor out "just the old stuff" to move to DVD.

I just reread the "mission statement" part of the SD! manual again, before replying. SD! is falling-off-a-log simple to use, but I'd disagree with the "for the rest of us" assumptions that the manual makes, to quote the phrase that first infuriated me when Apple coined it. When I think of users that aren't the coldest beers in the fridge, Apple isn't the first OS to come to mind.

There is a notion of the right tool for the job, and SD! works well because it has clean, simple design goals; the programming team isn't wasting 90% of its time supporting arcane tape formats. With the advent of cheap drives (I bought a 250 GB drive yesterday for 20 cents/GB), there has been a paradigm shift in home backup practices, making programs like SD! practical as primary backup tools. This doesn't obliviate the need for archiving.

In decades of using Retrospect, I've never wanted to time travel to an earlier version of an entire volume, I've twice replaced 2.5" laptop drives that died, and I've gone into archives more times than I can count to fish out an old version of a file. When did I hose that file? Let's see... Sometimes I have to go a dozen copies backwards. Hard drives are cheap, but I don't rotate that many drives. As a programmer, I've learned to use version control systems, I admire programmers that use version control for everything they do, but version control will never go mainstream until it becomes completely transparent and automatic. One needs a simple archiving facility, in addition to the disk clones that SD! offers. SD! is better poised to evolve a paradigm that covers all my backup needs, than anything else I see out there.

Edit: One way to implement what I want would be to use SD! to copy to disk images, then use a different tool to factor the disk images, deleting all files in the older image that are also contained in the newer image, and trimming the folder structure. This would permit saving a large number of such images. I looked at duplicate hunters recently, but I don't recall any that would be sufficiently scriptable for this purpose.