[ovirt-users] extending cloud Images in oVirt

I have a question indirectly releted to Ovirt. I need to move one old setup into VM running in oVirt cluster. The VM was based on on Debian 8.9, so I took a Debian cloude image from https://cdimage.debian.org/cdimage/openstack/8.9.8-20171105/ uploaded it into my cluster and attached it to VM. All looks good but ... the disk shows only 2G and indeed ned more disk space. I tried to edit and add more space - and it didnt work. Any ideas how to extend those cloud images? Regards, Artem