Thanks @tomp , I missed that LXD 5.0 LTS already supports optimized refresh between ZFS pools like I now read at LXD 5.0 LTS has been released
But trying to switch over to the LXD-integrated approach revealed that a ‘copy --refresh’ requires the source container to be stopped. As I am using my own solution on productive, running containers this LXD-integrated approach is no working solution.
Is there a way to ‘copy --refresh’ running containers? Otherwise I should stay with my sync script.