{
  config,
  service_configs,
  pkgs,
  ...
}:
{
  boot.zfs.package = pkgs.zfs;
  boot.initrd.kernelModules = [ "zfs" ];

  boot.kernelParams = [
    "zfs.zfs_txg_timeout=120" # longer TXG open time = larger sequential writes

    # vdev I/O scheduler: feed more concurrent reads to the block scheduler so
    # mq-deadline has a larger pool of requests to sort and merge into elevator sweeps.
    # Default async_read_max is 3 — far too few for effective coalescence.
    # 32 was empirically optimal (64 overwhelmed the drives, 3 gave near-zero merges).
    "zfs.zfs_vdev_async_read_max_active=32"
    "zfs.zfs_vdev_async_read_min_active=4"

    # Merge reads within 128 KiB of each other (default 32 KiB). On HDDs, reading a
    # 128 KiB gap is far cheaper than a mechanical seek (~8 ms).
    "zfs.zfs_vdev_read_gap_limit=131072"

    # Allow ZFS to aggregate I/Os up to 4 MiB (default 1 MiB), matching the
    # libtorrent piece extent size for larger sequential disk operations.
    "zfs.zfs_vdev_aggregation_limit=4194304"
  ];

  boot.supportedFilesystems = [ "zfs" ];
  boot.zfs.extraPools = [
    service_configs.zpool_ssds
    service_configs.zpool_hdds
  ];

  services.sanoid = {
    enable = true;
    datasets."${service_configs.zpool_ssds}" = {
      recursive = true;
      autoprune = true;
      autosnap = true;
      hourly = 5;
      daily = 7;
      monthly = 3;
      yearly = 0;
    };

    datasets."${service_configs.zpool_ssds}/services/sql" = {
      recursive = true;
      autoprune = true;
      autosnap = true;
      hourly = 12;
      daily = 2;
      monthly = 0;
      yearly = 0;
    };

    datasets."${service_configs.zpool_ssds}/services/jellyfin/cache" = {
      recursive = true;
      autoprune = true;
      autosnap = true;
      hourly = 0;
      daily = 0;
      monthly = 0;
      yearly = 0;
    };

    datasets."${service_configs.zpool_ssds}/services/monero" = {
      recursive = true;
      autoprune = true;
      autosnap = true;
      hourly = 0;
      daily = 0;
      monthly = 0;
      yearly = 0;
    };

    datasets."${service_configs.zpool_ssds}/services/p2pool" = {
      recursive = true;
      autoprune = true;
      autosnap = true;
      hourly = 0;
      daily = 0;
      monthly = 0;
      yearly = 0;
    };

    datasets."${service_configs.zpool_hdds}" = {
      recursive = true;
      autoprune = true;
      autosnap = true;
      hourly = 0;
      daily = 0;
      monthly = 0;
      yearly = 0;
    };
  };

  services.zfs = {
    autoScrub.enable = true;
    trim.enable = true;
  };
}