I ended up creating the VMs from scratch but I had only 3 so it wasn't that bad. I lost few days of work though.
I'm sure the virtual disk was ok but oVirt could not recognize it correctly.
I was able to import VMs only partially from connected storage domain but it did not import the disks. When I found the correct disk image in Glusterfs and uploaded it there was the size issue.
The VM did not recognize the thin provision disk correctly.
I also would like to know how to deal with such issues in case it happens again.