diff --git a/hosts/kabtopci/hardware-configuration.nix b/hosts/kabtopci/hardware-configuration.nix
index f0f6502..1ef67ee 100644
--- a/hosts/kabtopci/hardware-configuration.nix
+++ b/hosts/kabtopci/hardware-configuration.nix
@@ -59,7 +59,7 @@
   fileSystems."/nix" =
     { device = "/dev/disk/by-label/NIXROOT";
       fsType = "btrfs";
-      options = [ "compress=zstd,space_cache=v2,ssd,noatime,subvol=@nix,discard=async" ];
+      options = [ "compress=zstd:9,space_cache=v2,ssd,noatime,subvol=@nix,discard=async" ];
     };
 
   fileSystems."/swap" =
diff --git a/modules/services/kabtopci/hydra.nix b/modules/services/kabtopci/hydra.nix
index d7f4c08..c4db07e 100644
--- a/modules/services/kabtopci/hydra.nix
+++ b/modules/services/kabtopci/hydra.nix
@@ -8,7 +8,7 @@
         listenHost = "127.0.0.1";
         notificationSender = "hydra@kabtop.de";
         useSubstitutes = true;
-        minimumDiskFree = 30;
+        minimumDiskFree = 8;
       };
       nix-serve = {
           enable = true;
diff --git a/modules/services/kabtopci/microvm.nix b/modules/services/kabtopci/microvm.nix
index abad92a..529a66e 100644
--- a/modules/services/kabtopci/microvm.nix
+++ b/modules/services/kabtopci/microvm.nix
@@ -96,8 +96,8 @@ in
           microvm = {
             hypervisor = "qemu";
             vcpu = 4;
-            mem = 4096;
-            balloonMem = 4096;
+            mem = 3096;
+            balloonMem = 3096;
             #kernel = pkgs.linuxKernel.packages.linux_latest;
             interfaces = [
             {