> I suppose this isn't really a "backup" but rather a "mirroring strategy." But for certain kinds of data -- photos, video, large media -- can you really afford

> I suppose this isn't really a "backup" but rather a "mirroring strategy." But for certain kinds of data -- photos, video, large media -- can you really afford to do any other kind of strategy? Saving diffs/snapshots will solve the issue. As long as the file doesn't change the cost is almost 0.