let
  espPartition = {
    type = "filesystem";
    format = "vfat";
    mountpoint = "/boot";
    mountOptions = [
      "umask=0077"
    ];
  };
  rootPartition = {
    type = "btrfs";
    extraArgs = [ "-f" ]; # override existing partition
    subvolumes = {
      "/root" = {
        mountpoint = "/";
        mountOptions = [
          "subvol=root"
          "compress=zstd"
          "noatime"
        ];
      };
      "/home" = {
        mountOptions = [
          "subvol=home"
          "compress=zstd"
          "noatime"
        ];
        mountpoint = "/home";
      };
      "/nix" = {
        mountOptions = [
          "subvol=nix"
          "compress=zstd"
          "noatime"
        ];
        mountpoint = "/nix";
      };
      "/log" = {
        mountpoint = "/var/log";
        mountOptions = [
          "subvol=log"
          "compress=zstd"
          "noatime"
        ];
      };
      "/lib" = {
        mountpoint = "/var/lib";
        mountOptions = [
          "subvol=lib"
          "compress=zstd"
          "noatime"
        ];
      };
      "/persist" = {
        mountpoint = "/var/lib/persist";
        mountOptions = [
          "subvol=persist"
          "compress=zstd"
          "noatime"
        ];
      };
      "/secrets" = {
        mountpoint = "/var/lib/secrets";
        mountOptions = [
          "subvol=secrets"
          "compress=zstd"
          "noatime"
        ];
      };
    };
  };
in
{
  disko.devices.disk.vm-disk = {
    type = "disk";
    device = "/dev/vda";
    imageSize = "10G";
    content = {
      type = "gpt";
      partitions = {
        ESP = {
          priority = 1;
          name = "ESP";
          label = "boot";
          size = "1G";
          type = "EF00";
          content = espPartition;
        };
        root = {
          size = "100%";
          name = "root";
          label = "root";
          content = rootPartition;
        };
      };
    };
  };

  fileSystems."/var/lib/persist".neededForBoot = true;
  fileSystems."/var/log".neededForBoot = true;
  fileSystems."/var/lib".neededForBoot = true;
}