Description of problem:
Currently the Logical size for VDO is 10 times the sum of all bricks created. But the logical size should always be 10 times of the physical size of device.
ie:
If the device /dev/sdb has a size of the of 20T. Then the logical size should be 200T. This should be irrespective of the brick size selected for each volume.

Also considering a scenario where, if the device size is 20 TB and a volume created out of it is 1T then the logical size will be 10T. Which is less than the physical size. (physical size 20TB > logical size 10 T). This is not recommended according to VDO. 
This also eliminates the work of adding the logical size every time we create a new volume.

NOTE: Also had previously confirmed the same with Dennis Keefe. Please find the comment below:

    2. vdoLogicalSize = 10 x ( Disk physical size )
    In actual, the cockpit implementation does 4 x size of physical disk.
    I read from the RHEL 7.5 storage admin guide, about the recommendation of 10:1


 The cockpit implementation will allow much large size, though you have to manually change the settings.
10x is typical for VMs.  I agree with this setting.


Version-Release number of selected component (if applicable):
cockpit-ovirt-dashboard-0.11.21-1.el7ev.noarch

How reproducible:
100%

Steps to Reproduce:
1. Login to cockpit UI
2. Start gluster deployment 
3. Select the  enable compression and dedupe check

Actual results:


Expected results:


Additional info: