Updated README

README.md

@@ -2,17 +2,17 @@
 ## Description
 My NixOS configuration repository
 
-## Install a new host 
+## Install a New Host 
 1. Install NixOS with graphical ISO image (e.g. GNOME). During the installation the desktop environment can be choosen.
 2. Reboot into NixOS
 3. Edit `/etc/nixos/configuration.nix` with sudoedit
-    a) Change hostname
-    b) Enable flakes. Add the following lines:
+    - Change hostname
+    - Enable flakes. Add the following lines:
 ```
 # Enable flakes
  nix.settings.experimental-features = [ "nix-command" "flakes" ];
 ```
-    c) Install tmux, neovim, git by adding them to `environment.systemPackages = with pkgs; [`
+    - Install tmux, neovim, git by adding them to `environment.systemPackages = with pkgs; [`
 4. Apply changes: `sudo nixos-rebuild switch` and reboot
 5. Clone NixOS config repository to /home/$USER/nixos:
 ```
@@ -20,9 +20,25 @@ cd
 git clone https://git.plueschbit.de/jan/nixos-conf ~/nixos
 ```
 6. Add the new host to repository
-    a) Create ~/nixos/hosts/$HOSTNAME
-    b) `cp /etc/nixos/*.nix $HOSTNAME/.`
-    c) Edit `~/nixos/flake.nix` and add section for new host
-    d) Stage new config files: `git add flake.nix hosts/$HOSTNAME/*`. Otherwise, nixos-rebuild will refuse to work with the files.
+    - Create ~/nixos/hosts/$HOSTNAME
+    - `cp /etc/nixos/*.nix $HOSTNAME/.`
+    - Edit `~/nixos/flake.nix` and add section for new host
+    - Stage new config files: `git add flake.nix hosts/$HOSTNAME/*`. Otherwise, nixos-rebuild will refuse to work with the files.
 8. Apply config: `sudo nixos-rebuild switch --flake ~/nixos/#<host>`
 
+## Update Packages on a Host
+Update of the file `flake.nix`:
+```
+sudo nix flake update
+```
+Then, perform nixos rebuild:
+```
+sudo nixos-rebuild switch --flake ~/nixos/#<host>
+```
+
+## Garbage Collection
+Keep e.g. the last five generations and perform garbage collection:
+```
+sudo nix-env --delete-generations +5
+sudo nix-store --gc
+```