feat: change iso to btrfs

iso/hardware-configuration.nix

@@ -6,9 +6,29 @@
 		fsType = "vfat";
 	};
 
-  fileSystems."/"  = {
-    device = "/dev/disk/by-partlabel/NIXOS";
+  fileSystems."/" = {
+    device = "none";
+    fsType = "tmpfs";
+    options = [ "size=16G" "mode=755" ];
+  };
+
+	boot.initrd.luks.devices.root = {
+		device = "/dev/disk/by-label/root";
+
+		# WARNING: Leaks some metadata, see cryptsetup man page for --allow-discards.
+		allowDiscards = true;
+
+		# Set your own key with:
+		# cryptsetup luksChangeKey /dev/disk/by-label/root --key-file=/dev/zero --keyfile-size=1
+		# You can then delete the rest of this block.
+		keyFile = "/dev/zero";
+		keyFileSize = 1;
+	};
+
+  fileSystems."/nix"  = {
+    device = "/dev/mapper/root";
     fsType = "btrfs";
+    neededForBoot = true;
     options = [
       "subvol=@"
       "ssd"
@@ -19,8 +39,9 @@
   };
 
   fileSystems."/nix/store" = {
-    device = "/dev/disk/by-uuid/…";
+    device = "/dev/mapper/root";
     fsType = "btrfs";
+    neededForBoot = true;
     options = [
       "subvol=@nix-store"
       "ssd"
@@ -31,8 +52,9 @@
   };
 
   fileSystems."/nix/persist"  = {
-    device = "/dev/disk/by-partlabel/NIXOS";
+    device = "/dev/mapper/root";
     fsType = "btrfs";
+    neededForBoot = true;
     options = [
       "subvol=@nix-persist"
       "ssd"