{ pkgs, ... }: { boot = { kernelPackages = pkgs.linuxPackages_latest; kernel.sysctl."vm.max_map_count" = 2147483642; initrd = { systemd = { enable = true; services.root-reset = { description = "Reset BTRFS root and snapshot last boot"; wantedBy = [ "initrd.target" ]; after = [ "dev-nixos-root.device" ]; before = [ "sysroot.mount" ]; unitConfig.DefaultDependencies = "no"; serviceConfig.Type = "oneshot"; script = '' mkdir -p /mnt mount /dev/nixos/root /mnt if [[ -e /mnt/@prev ]]; then btrfs subvolume delete /mnt/@prev fi btrfs subvolume snapshot /mnt/@ /mnt/@prev btrfs subvolume list -o /mnt/@ | cut -f9 -d' ' | while read subvolume; do btrfs subvolume delete "/mnt/$subvolume" done btrfs subvolume delete /mnt/@ btrfs subvolume create /mnt/@ umount /mnt ''; }; }; }; }; }