1# Necessary system state {#ch-system-state} 2 3Normally — on systems with a persistent `rootfs` — system services can persist state to 4the filesystem without administrator intervention. 5 6However, it is possible and not-uncommon to create [impermanent systems], whose 7`rootfs` is either a `tmpfs` or reset during boot. While NixOS itself supports 8this kind of configuration, special care needs to be taken. 9 10[impermanent systems]: https://wiki.nixos.org/wiki/Impermanence 11 12 13```{=include=} sections 14nixos-state.section.md 15systemd-state.section.md 16zfs-state.section.md 17```