Harddisk space requirements for small-scale setup?

Rancher versions:
rancher/server: latest (not yet installed)
rancher/agent: latest (not yet installed

Operating system and kernel:
RancherOS v1.0.3

Type/provider of hosts:

Setup details:
one t2.micro with, say, 16 GB storage
one t2.medium with 100 GB storage

Environment Template:

Question on minimum requirements:

I found Rancher yesterday and was blown away. You guys rock!!

Now I want to setup a full CD pipieline with Gitlab and Rancher on AWS for personal use.
What I could not find in the docs was sensible hdd space requirements, and a good description of where data is stored, how fast it accumulates, and how/when it is cleaned up. Also what is the best volume setup? I know from docker-compose that images and containers can clog up a quite a bit of space if you are not careful.

My impression is that rancher-server could be installed on the t2.micro instance, and the host + rancher db will take the t2.medium instance. I was also thinking to create another host on the t2.micro besides the server, where only Gitlab is hosted (but with the registry on the t2.medium).

Does this make sense, or should I approach it differently?

I decided to take a different approach and instead have a single-instance install on the t2.medium and then create a second host on the t2.micro.