nixos-conf/shared/hardware/impermanence.nix

{ lib, ... }:
{
  fileSystems."/persist".neededForBoot = true;

  services.zfs = {
    autoScrub.enable = true;
    autoSnapshot = {
      enable = true;
      flags = "-k -p --utc";
    };
  };

  boot.initrd.postResumeCommands = lib.mkAfter ''
    zfs rollback -r zroot/root@blank
    zfs rollback -r zroot/home@blank
  '';
}