@@ -3,6 +3,11 @@ pkgs,
   lib,
   ...
 }:
+let
+  kb = 1000;
+  mb = 1000 * kb;
+  gb = 1000 * mb;
+in
 {
   nix = {
     package = pkgs.lix;
@@ -10,19 +15,25 @@ settings = {
       cores = lib.mkDefault 0;
       use-xdg-base-directories = true;
       keep-outputs = true;
-      keep-derivations = true;
       warn-dirty = false;
-      substituters = [
+
+      # https://jackson.dev/post/nix-reasonable-defaults/
+      connect-timeout = 5;
+      min-free = 128 * mb;
+      max-free = 1 * gb;
+      fallback = true;
+
+      trusted-substituters = [
         "https://nix-community.cachix.org"
-        "https://binarycache.alin.ovh"
         "https://cache.lix.systems"
+        "https://binarycache.alin.ovh"
       ];
-
       trusted-public-keys = [
         "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
         "binarycache.alin.ovh:ZwqO3XMuajPictjwih8OY2+RXnOKpjZEZFHJjGSxAI4="
         "cache.lix.systems:aBnZUw8zA7H35Cz2RyKFVs3H4PlGTLawyY5KRbvJR8o="
       ];
+
       experimental-features = [
         "nix-command"
         "flakes"