There's still no progess in adding NFSv4 to klibc nfsmount for initramfs-tools. Here's the info how to use overlayfs and NFSv4 for a read-only nfsroot but with dracut instead of initramfs-tools: http://blog.fai-project.org/posts/overlayfs/ http://fai-project.org/fai-guide/#_a_id_nfsv4_a_how_to_use_nfs_v4_with_the_nfsroot -- regards Thomas