[virt-tools-list] dynamically allocated disks

[LK]

Hi,

I thought that qcow2 would be a sparse disk format, but when I create a 
new disk using virt-manager (Ubuntu 16.10, virt-manager 1.3.2), the size 
of the new disk is exactly the same size I chose at creation time (as 
the disk would be completely full).

Ho can I create a dynamically allocated disk using virt-manager?

Thanks

LK