nixos-config/hosts/vm/default.nix

{ ... }:
{
  networking.hostName = "vm";
  sconfig.profile = "server";
  boot.loader.grub.device = "/dev/vda";
  fileSystems."/" = { device = "/dev/vda1"; fsType = "ext4"; };
  security.sudo.wheelNeedsPassword = false;
}