fix mq-deadline for hdds

Add mollysocket so we can use ntfy for molly (signal)

configuration.nix

@@ -69,6 +69,8 @@
 
     ./services/ntfy.nix
     ./services/ntfy-alerts.nix
+
+    ./services/mollysocket.nix
   ];
 
   services.kmscon.enable = true;

modules/age-secrets.nix

@@ -88,5 +88,11 @@
       file = ../secrets/firefox-syncserver-env.age;
       mode = "0400";
     };
+
+    # MollySocket env (MOLLY_VAPID_PRIVKEY + MOLLY_ALLOWED_UUIDS)
+    mollysocket-env = {
+      file = ../secrets/mollysocket-env.age;
+      mode = "0400";
+    };
   };
 }

modules/hardware.nix

@@ -23,13 +23,48 @@
   hardware.enableRedistributableFirmware = true;
 
   # HDD I/O tuning for torrent seeding workload (high-concurrency random reads).
+  #
   # mq-deadline sorts requests into elevator sweeps, reducing seek distance.
   # Aggressive deadlines (15s) let the scheduler accumulate more ops before dispatching,
   # maximizing coalescence — latency is irrelevant since torrent peers tolerate 30-60s.
   # fifo_batch=128 keeps sweeps long; writes_starved=16 heavily favors reads.
   # 4 MiB readahead matches libtorrent piece extent affinity for sequential prefetch.
-  services.udev.extraRules = ''
-    ACTION=="add|change", KERNEL=="sd[a-z]", ATTR{queue/rotational}=="1", ATTR{queue/scheduler}="mq-deadline", ATTR{queue/read_ahead_kb}="4096", ATTR{queue/nr_requests}="512"
-    ACTION=="add|change", KERNEL=="sd[a-z]", ATTR{queue/rotational}=="1", ENV{ID_ATA_ROTATION_RATE_RPM}!="0", RUN+="${pkgs.bash}/bin/bash -c 'echo 15000 > /sys$devpath/queue/iosched/read_expire; echo 15000 > /sys$devpath/queue/iosched/write_expire; echo 128 > /sys$devpath/queue/iosched/fifo_batch; echo 16 > /sys$devpath/queue/iosched/writes_starved; echo 4096 > /sys$devpath/queue/max_sectors_kb 2>/dev/null || true'"
-  '';
+  #
+  # This runs as a systemd oneshot rather than udev rules because the NixOS ZFS module
+  # hardcodes a udev rule that forces scheduler="none" on all ZFS member partitions'
+  # parent disks, overriding any scheduler set via udev on the disk event.
+  systemd.services.hdd-io-tuning = {
+    description = "HDD I/O scheduler and queue tuning";
+    after = [
+      "zfs-import.target"
+      "systemd-udev-settle.service"
+    ];
+    wantedBy = [ "multi-user.target" ];
+    serviceConfig = {
+      Type = "oneshot";
+      RemainAfterExit = true;
+    };
+    script = ''
+      for dev in /sys/block/sd*; do
+        [ -f "$dev/queue/rotational" ] || continue
+        [ "$(cat "$dev/queue/rotational")" = "1" ] || continue
+
+        # skip removable devices (USB sticks report removable=1)
+        [ "$(cat "$dev/removable")" = "0" ] || continue
+
+        echo mq-deadline > "$dev/queue/scheduler"
+        echo 4096 > "$dev/queue/read_ahead_kb"
+        echo 512 > "$dev/queue/nr_requests"
+
+        echo 15000 > "$dev/queue/iosched/read_expire"
+        echo 15000 > "$dev/queue/iosched/write_expire"
+        echo 128 > "$dev/queue/iosched/fifo_batch"
+        echo 16 > "$dev/queue/iosched/writes_starved"
+
+        echo 4096 > "$dev/queue/max_sectors_kb" 2>/dev/null || true
+
+        echo "Tuned $(basename "$dev"): mq-deadline, 4M readahead, 15s deadlines"
+      done
+    '';
+  };
 }

service-configs.nix

@@ -149,6 +149,10 @@ rec {
         port = 5000;
         proto = "tcp";
       };
+      mollysocket = {
+        port = 8020;
+        proto = "tcp";
+      };
     };
   };
 
@@ -219,6 +223,10 @@ rec {
     domain = "ntfy.${https.domain}";
   };
 
+  mollysocket = {
+    domain = "mollysocket.${https.domain}";
+  };
+
   livekit = {
     domain = "livekit.${https.domain}";
   };

services/mollysocket.nix

@@ -0,0 +1,36 @@
+{
+  config,
+  service_configs,
+  lib,
+  ...
+}:
+{
+  imports = [
+    (lib.serviceMountWithZpool "mollysocket" service_configs.zpool_ssds [
+      "/var/lib/private/mollysocket"
+    ])
+    (lib.serviceFilePerms "mollysocket" [
+      "Z /var/lib/private/mollysocket 0700 root root"
+    ])
+  ];
+
+  services.mollysocket = {
+    enable = true;
+
+    settings = {
+      host = "127.0.0.1";
+      port = service_configs.ports.private.mollysocket.port;
+
+      # Explicitly allow our self-hosted ntfy instance.
+      # Local-network endpoints are denied by default for security.
+      allowed_endpoints = [ "https://${service_configs.ntfy.domain}" ];
+      # allowed_uuids set via MOLLY_ALLOWED_UUIDS in environmentFile
+    };
+
+    environmentFile = config.age.secrets.mollysocket-env.path;
+  };
+
+  services.caddy.virtualHosts."${service_configs.mollysocket.domain}".extraConfig = ''
+    reverse_proxy h2c://127.0.0.1:${builtins.toString service_configs.ports.private.mollysocket.port}
+  '';
+}