[Users] Gluster NFS Replicate bricks different size

I've mounted a gluster 1x2 replica through NFS in oVirt. The NFS share holds the qcow images of the VMs. I recently nuked a whole replica brick in an 1x2 array (for numerous other reasons including split-brain), the brick self healed and restored back to the same state as its partner. 4 days later, they've become inbalanced. The direct `du` of the /brick are showing different sizes by around 20GB. I can see at brick level how some images are not the same size. I don't think this is normal, but I can't see anything to point what could be the issue. gluster volume heal STORAGE info gluster volume heal STORAGE info split-brain Shows no issues. Any suggestions? Cheers, Andrew.