You can move a into a , from one host group to another host group, or completely out of a host group.
When you move a host into a host group, or move a host from one host group into another, the host and the related keep the original and inherit the host-to-virtual disk mappings of the new host group.
When you move a host completely out of a host group, the host keeps all of the host-to-virtual disk mappings it had in its
original host group.