{ config, lib, ... }: let inherit (lib) flatten optional; in { persist = { directories = flatten [ "/home" "/etc/nixos" "/etc/nixos-private" "/var/log" "/var/lib/systemd/coredump" "/var/lib/tailscale" "/root/.ssh" (optional config.services.fprintd.enable "/var/lib/fprint") ]; files = [ "/etc/machine-id" ]; }; }