Incremental Images

I know this has been covered elsewhere, and there's a question pending right now that I'm interested in, but...

Why are the incrementals so big? I saw an explanation about sectors changing but I'm not defragging, or doing anything freaky, yet more often than not, the incremental is as large as the full image, even when it's not, I'm seeing a gig or more. Is this backing up the SWAP file (or whatever it's called these days). I have 13G sitting around on my drive for backups, but I'd only get a couple of days of incrementals before I ran out of space...

Speaking of running out of space, I see mention that if space is an issue with incrementals, the full image is deleted and a new one taken, does this mean the incrementals are also deleted? Otherwise they're pretty useless without the full image as a starting point, no? (Unless they're really full limages also, see point 1).

 

Updated to point out that perhaps it's working better using the secure zone? but the second question still stands.


I see mention that if space is an issue with incrementals, the full image is deleted and a new one taken, does this mean the incrementals are also deleted? Otherwise they're pretty useless without the full image as a starting point, no? I'm asking because I'm trying to figure out if I should take a full once a wek, then incrementals, or just let the incrementals go day after day. I'd do the latter if I better understood how it's going to manage the "old" images when it runs out of space.