do not restart VMs on change

nixos/physical.nix

@@ -61,8 +61,18 @@
       builtins.mapAttrs
         (name: vm:
           {
-            # TODO Simplify?
-            specialArgs = { inherit agenix disko pkgs lib microvm dns; machine = vm; hypervisorConfig = config; };
+            # Do not restart virtual machines to apply configuration changes.
+            # While conceptually this seems useful, it could result in annoying situations.
+            # For example, changing the default VM configuration will restart ALL VMs simultaneously, causing a lot of stress on the servers.
+            # Downside of not restarting, is that we may need to do this manually now to apply changes.
+            restartIfChanged = false;
+
+            specialArgs = {
+              inherit agenix disko pkgs lib microvm dns;
+              machine = vm;
+              hypervisorConfig = config;
+            };
+
             config.imports = [
               ./.
               { networking.hostName = name; }