eliminare la .list enterprise \\

aggiungere a /etc/apt/source.list \\
  deb http://download.proxmox.com/debian/pve buster pve-no-subscription


poi creare una nuova lista /etc/apt/source.list.d/ceph.list \\
  deb http://download.proxmox.com/debian/ceph-nautilus buster main