zfs: change arc size setting

services/qbittorrent.nix

@@ -27,12 +27,7 @@
     serverConfig.Preferences = {
       WebUI = {
         AlternativeUIEnabled = true;
-        RootFolder = builtins.toString (
-          pkgs.fetchzip {
-            url = "https://github.com/VueTorrent/VueTorrent/releases/download/v2.28.2/vuetorrent.zip";
-            sha256 = "8aKmiXcr2pp8qt4w/lYBAIjLPh8tlgYsx6PbovY54KM=";
-          }
-        );
+        RootFolder = builtins.toString pkgs.vuetorrent;
 
         # disable auth because we use caddy for auth
         AuthSubnetWhitelist = "0.0.0.0/0";

zfs.nix

@@ -25,10 +25,13 @@ in
 
   boot.kernelParams =
     let
-      mb = 20000;
+      gb = 20;
+      mb = gb * 1000;
+      kb = mb * 1000;
+      b = kb * 1000;
     in
     [
-      "zfs.zfs_arc_max=${builtins.toString (mb * 1000000)}"
+      "zfs.zfs_arc_max=${builtins.toString b}"
     ];
 
   boot.supportedFilesystems = [ "zfs" ];