home/hosts/odin/system/hd-idle.nix

{ lib, pkgs, ... }:
let
  disks = [
    "/dev/disk/by-id/ata-ST8000VN002-2ZM188_WPV023WG"
    "/dev/disk/by-id/ata-ST8000VN002-2ZM188_WPV07RMA"
    "/dev/disk/by-id/ata-ST8000VN002-2ZM188_WPV020CG"
  ];

  mkArgString = disks:
    lib.concatStringsSep " " (lib.map (disk: "-a ${disk} -i 600") disks);

  args = mkArgString disks;
  fatrace = lib.getExe' pkgs.fatrace "fatrace";
  hd-idle = lib.getExe' pkgs.hd-idle "hd-idle";
in
{
  environment.systemPackages = [ pkgs.hd-idle pkgs.fatrace ];

  systemd.services.hd-idle = {
    description = "hd-idle - spin down idle hard disks";
    after = [
      "suspend.target"
      "hibernate.target"
      "hybrid-sleep.target"
      "suspend-then-hibernate.target"
    ];
    wantedBy = [ "multi-user.target" ];

    serviceConfig = {
      Type = "simple";
      ExecStart = "${hd-idle} ${args}";
      Restart = "always";
    };
  };

  systemd.services.fatrace = {
    description = "File access tracing service";
    after = [ "local-fs.target" ];
    wants = [ "local-fs.target" ];

    serviceConfig = {
      ExecStart = "${fatrace} --timestamp /mnt/storage";
      Restart = "always";
      User = "root";
    };
  };
}