anchor.diff:  
                   # Create a state directory required by NFSv4.
                   mkdir -p /var/lib/nfs/v4recovery
  +
  +                # rpc.nfsd needs the kernel support
  +                ${config.system.sbin.modprobe}/sbin/modprobe nfsd || true
   
                   ${pkgs.sysvtools}/bin/mountpoint -q /proc/fs/nfsd \
                   || ${config.system.sbin.mount}/bin/mount -t nfsd none /proc/fs/nfsd
  
positive.code: 
        I've not tried with nfsd alone. So I add what I tried, with nfs_acl too.
      */
      boot.kernelModules = mkIf cfg.server.enable [ "nfsd" "nfs_acl" ];
  
      jobs =
        optionalAttrs cfg.server.enable
  
negative.code:             description = "Kernel NFS server - Network Status Monitor";
  
              startOn = if (cfg.server.enable) then
                "started nfs-kernel-mountd and started nfs-kernel-nfsd"
                else
                  "started portmap";
              stopOn = "stopping nfs-kernel-exports or stopping portmap";
  
              preStart =
  