## Description of problem:

There should be better guidance on the space required for hosted engine

## Version-Release number of selected component (if applicable):

4.0, and possibly update 3.5/3.6 docs as well

## How reproducible:

always

## Steps to Reproduce:
1. Install 3.6 with 60Gb iscsi disk for hosted engine
2. Try to update to 4.0

## Actual results:

Installer tells you to increase storage.  In some cases with block storage, this might be difficult to do on the fly.


## Expected results:

Ideally, make storage large enough when doing initial deployment, so that upgrades can be done with less difficulty.


## Additional info: