add backup stuff

systems/x86_64-linux/ulmo/default.nix

@@ -1,9 +1,21 @@
-{...}: {
+{
+  pkgs,
+  config,
+  ...
+}: {
   imports = [
     ./disks.nix
     ./hardware.nix
   ];
 
+  environment.systemPackages = with pkgs; [bup];
+  services.postgresqlBackup = {
+    enable = true;
+    backupAll = true;
+    startAt = "*-*-* 01:00:00";
+    location = "/var/backup/postgresql";
+  };
+
   networking = {
     interfaces.enp2s0 = {
       ipv6.addresses = [