[Feature Request] Provide the minimal disk space requirement for CMake testing.

**Is your feature request related to a problem? Please describe.**
`make test` failed when the available storage is 1.6G.

**Describe the solution you'd like**
Provide a documentation on how much space is required.

**Describe alternatives you've considered**
It would be nice if 'make test' can skip some tests if they require space beyond what's available.

**Additional context**
I think this will be useful for small VMs and embedded system.