Bug 1519304

Description of problem:
There is no indication newly created VDO may be thinly provisioned, so user might be not aware of it as of now the default VDO is thinly provisioned. For comparision this is how LVM handles it:

# lvcreate -n pool -T -L 2G vg                                                       
  Using default stripesize 64.00 KiB.
  Thin pool volume with chunk size 64.00 KiB can address at most 15.81 TiB of data.
  Logical volume "pool" created.
# lvcreate -n lv -T -V 6G vg/pool                                                    
  Using default stripesize 64.00 KiB.
  WARNING: Sum of all thin volume sizes (6.00 GiB) exceeds the size of thin pool vg/pool (2.00 GiB).
  WARNING: You have not turned on protection against thin pools running out of space.
  WARNING: Set activation/thin_pool_autoextend_threshold below 100 to trigger automatic extension of thin pools before they get full.
  Logical volume "lv" created.

Version-Release number of selected component (if applicable):
vdo-6.1.0.55-9

How reproducible:
100%

Steps to Reproduce:
1. # vdo create --name vdo --device device
2. check that vdo logical size is greater than vdo slab_size*slab_count (e.g. actual physical size)
# vdo status

Actual results:
No warning

Expected results:
warning similar to 'WARNING: Sum of all thin volume sizes (6.00 GiB) exceeds the size of thin pool vg/pool (2.00 GiB).'

Additional info: