[Libguestfs] virt-resize does not work

[Info || Vertixo B.V.]

Hi,

Im trying to expand an linux image but it does not seem to get bigger after 
everything is completed.
The thing i noticed was, i am trying to expand a /dev/vda1 within the image 
but virt-resize keeps referring it as /dev/sda1. See below:

# virt-resize --dry-run --expand /dev/vda1 test.qcow2 test-new.qcow2
Examining test.qcow2 ...
**********
Summary of changes:

/dev/sda1: This partition will be resized from 13.4G to 23.4G.  The 
    filesystem ext3 on /dev/sda1 will be expanded using the 'resize2fs' 
    method.
/dev/sda2: This partition will be left alone.
**********

Is this a bug or am i doing something wrong?

Thx!