I went through my file server backups this weekend. They're incremental, which makes each new one pretty small. Usually on the order of 0-20 MB or something. My main drive is a 128 GB USB stick, as is my backup drive. My main drive was filled to about 70 GB, and my backup was 89 GB. This is not strange at all for a few reasons:
It's pretty informative to look at the sizes of the snapshots.
For example I found that sometime in December the incremental change on the main drive was 2.4 GB in just a week. What exactly had I done that week? That's huge, compared to my overall disk space.
It turns out I downloaded a movie. It's not even 2 hours long, but of course 2.4 GB isn't much in the context of a movie file. It's just much in the context of my system; compared to any other media I have.
I dug through another few backup logs for snapshots that were sizeable compared to the normal. A television series of 14 20-minute episodes is 3.8 GB. Those are the only video files I have, and they take up a wopping 6.7 GB together (no, I can't work out that math either, but du probably does some rounding). 10% of my entire disk usage.
There's no opinion to share here, nor any info that anyone doesn't already know. It is, however, a small reminder that not everything needs to be saved for all eternity. That movie and those TV series episodes? If I ever want to watch them again it'll probably be easy to find them. And if I can't find them then I guess I'll do something else instead.
-- CC0 Björn Wärmedal