diff --git a/hosts/vm/configuration.nix b/hosts/vm/configuration.nix
index 22430f1..7b77541 100644
--- a/hosts/vm/configuration.nix
+++ b/hosts/vm/configuration.nix
@@ -17,7 +17,12 @@
 
   fileSystems."/" = {
     fsType = "tmpfs";
-    options = [ "mode=0755" ];
+  };
+
+  fileSystems."/nix" = {
+    fsType = "btrfs";
+    device = "/dev/vda2";
+    options = [ "nodev,noatime,compress-force=zstd:1,discard=async" ];
   };
 
   system.stateVersion = "25.05";