From 1685f9b472feae89cf01bfe567c062a96589d67e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Leonardo=20Eug=C3=AAnio?= <lelgenio@disroot.org>
Date: Thu, 16 Apr 2026 21:27:21 -0300
Subject: [PATCH] monolith: run nix builds in tmpfs, improve zram performance

---
 hosts/monolith/default.nix | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/hosts/monolith/default.nix b/hosts/monolith/default.nix
index bc673a0..15ba704 100644
--- a/hosts/monolith/default.nix
+++ b/hosts/monolith/default.nix
@@ -161,6 +161,25 @@ in
     useTmpfs = true;
   };
 
+  fileSystems."/nix/var/nix/builds" = {
+    device = "tmpfs";
+    fsType = "tmpfs";
+    options = [
+      "size=20G" # adjust for your situation and needs
+      "mode=700"
+    ];
+  };
+
+  zramSwap.enable = true;
+  zramSwap.memoryPercent = 100;
+
+  boot.kernel.sysctl = {
+    "vm.swappiness" = 180;
+    "vm.watermark_boost_factor" = 0;
+    "vm.watermark_scale_factor" = 125;
+    "vm.page-cluster" = 0;
+  };
+
   # swap
   # fileSystems."/swap" = {
   #   device = "/dev/disk/by-label/BTRFS_ROOT";