nixos/zram: init

6 files changed, 28 insertions, 16 deletions

diff --git a/modules/nixos/archetypes/server.nix b/modules/nixos/archetypes/server.nix
index 08b2d65..e42e3d4 100644
--- a/modules/nixos/archetypes/server.nix
+++ b/modules/nixos/archetypes/server.nix
@@ -40,6 +40,8 @@ in {
       users = {
         hostUser.enable = true;
       };
+
+      zram.enable = true;
     };
 
     _module.args.unstable = inputs.nixpkgs.legacyPackages.${pkgs.stdenv.hostPlatform.system};
diff --git a/modules/nixos/traits/default.nix b/modules/nixos/traits/default.nix
index d2a50e7..7b1d6fa 100644
--- a/modules/nixos/traits/default.nix
+++ b/modules/nixos/traits/default.nix
@@ -14,5 +14,6 @@
     ./tailscale.nix
     ./user-setup.nix
     ./users.nix
+    ./zram.nix
   ];
 }
diff --git a/modules/nixos/traits/zram.nix b/modules/nixos/traits/zram.nix
new file mode 100644
index 0000000..337137a
--- /dev/null
+++ b/modules/nixos/traits/zram.nix
@@ -0,0 +1,24 @@
+{
+  config,
+  lib,
+  ...
+}: let
+  cfg = config.traits.zram;
+in {
+  options.traits.zram = {
+    enable = lib.mkEnableOption "zram setup & configuration";
+  };
+
+  config = lib.mkIf cfg.enable {
+    # https://github.com/pop-os/default-settings/pull/163
+    # https://wiki.archlinux.org/title/Zram#Multiple_zram_devices
+    boot.kernel.sysctl = {
+      "vm.swappiness" = 180;
+      "vm.watermark_boost_factor" = 0;
+      "vm.watermark_scale_factor" = 125;
+      "vm.page-cluster" = 0;
+    };
+
+    zramSwap.enable = true;
+  };
+}
diff --git a/systems/atlas/default.nix b/systems/atlas/default.nix
index 1e448c6..7c1bc3d 100644
--- a/systems/atlas/default.nix
+++ b/systems/atlas/default.nix
@@ -23,6 +23,4 @@
   services.logrotate.checkConfig = false;
 
   system.stateVersion = "23.05";
-
-  zramSwap.enable = true;
 }
diff --git a/systems/glados/boot.nix b/systems/glados/boot.nix
index a7ac843..9fc716c 100644
--- a/systems/glados/boot.nix
+++ b/systems/glados/boot.nix
@@ -17,13 +17,6 @@
 
     kernelParams = ["amd_pstate=active"];
 
-    kernel.sysctl = {
-      "vm.swappiness" = 100;
-      "vm.vfs_cache_pressure" = 500;
-      "vm.dirty_background_ratio" = 1;
-      "vm.dirty_ratio" = 50;
-    };
-
     loader.systemd-boot.enable = lib.mkForce false;
 
     lanzaboote = {
diff --git a/systems/glados/default.nix b/systems/glados/default.nix
index 4f8af01..101bf2a 100644
--- a/systems/glados/default.nix
+++ b/systems/glados/default.nix
@@ -21,6 +21,7 @@
   traits = {
     containers.enable = true;
     tailscale.enable = true;
+    zram.enable = true;
   };
 
   security.tpm2 = {
@@ -48,11 +49,4 @@
   };
 
   system.stateVersion = "23.11";
-
-  zramSwap = {
-    enable = true;
-    algorithm = "zstd";
-    swapDevices = 1;
-    memoryPercent = 50;
-  };
 }