Description of problem:
The appliance_console shows an empty (O MB) device size when configuring the internal database of an appliance.

Version-Release number of selected component (if applicable):
CFME 5.6.0.13

How reproducible:
Setup a fresh cloudforms appliance with 2 volumes and setup the vmdb.

Steps to Reproduce:
1. Start a new appliance with 2 volumes anywhere
2. Launch the appliance_console and choose options 8 --> 1 --> 1
3. Read the output

The output is:
database disk

1) /dev/vdb: 0 MB
2) Don't partition the disk

Choose the database disk: |1| 1

The output should be:
database disk

1) /dev/vdb: 10240 MB
2) Don't partition the disk

Choose the database disk: |1| 1

Additional info:
The bug is not blocking as you can still choose option 1, go ahead and configure the database.