Why we need 100GB storage for deployment?

I'm wondering why we need 100GB storage for just deploying this application? In the docker deployment documentation we have the following:

> Storage:
> Either 100GB disk at /
> or 32GB disk at / for the OS and an additional 100GB disk at /data for Docker and Contraxsuite (safer). 

Could you elaborate a bit the reasons why this application needs such amount of storage just to get started?