hosts/hypnos: rebuild

hosts/hypnos/README.md

@@ -24,16 +24,24 @@ Apple SSD SM0512F | `/dev/sda1` (EFI, 256 MiB, NixOS Boot) <br> `/dev/sda2` (ZFS
 rpool/
 ├── local
 │   ├── nix
-│   └── tmp
-├── system
 │   ├── root
-│   └── var
-└── user
-    └── home
+│   └── state
+└── safe
+    └── persist
 ```
 
 See [Graham Christensen's article](https://grahamc.com/blog/nixos-on-zfs/#datasets) for the motivation behind these datasets.
 
+#### Impermanence
+
+This machine uses [impermanence](https://github.com/nix-community/impermanence) and is rolled back to a clean state on each reboot.
+
+Mountpoint | Persists across reboots? | Backed up?
+--- | --- | ---
+`/` | No | Yes
+`/state` | Yes | No
+`/persist` | Yes | Yes
+
 ### Networks
 
 - DHCP on `10.0.1.0/24` subnet.