This reverts commit f10bead8fd068f2cb82cbdc1a938a67bd967974c because it doesn't work - there is no lsblk in the initrd, and there is a missing backslash.
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at http://nixos.org/nixos and in the manual in doc/manual.