using GRUB and your existing distribution is running Ubuntu, you may
    want to add something like this to your `configuration.nix`:

    ```nix
    {
      boot.loader.grub.extraEntries = ''
        menuentry "Ubuntu" {
          search --set=ubuntu --fs-uuid 3cc3e652-0c1f-4800-8451-033754f68e6e
          configfile "($ubuntu)/boot/grub/grub.cfg"
        }
      '';
    }
    ```

    (You can find the appropriate UUID for your partition in
    `/dev/disk/by-uuid`)

1.  Create the `nixbld` group and user on your original distribution:

    ```ShellSession
    $ sudo groupadd -g 30000 nixbld
    $ sudo useradd -u 30000 -g nixbld -G nixbld nixbld
    ```

1.  Download/build/install NixOS:

    ::: {.warning}
    Once you complete this step, you might no longer be able to boot on
    existing systems without the help of a rescue USB drive or similar.
    :::

    ::: {.note}
    On some distributions there are separate PATHS for programs intended
    only for root. In order for the installation to succeed, you might
    have to use `PATH="$PATH:/usr/sbin:/sbin"` in the following command.
    :::

    ```ShellSession
    $ sudo PATH="$PATH" `which nixos-install` --root /mnt
    ```

    Again, please refer to the `nixos-install` step in
    [](#sec-installation) for more information.

    That should be it for installation to another partition!

1.  Optionally, you may want to clean up your non-NixOS distribution:

    ```ShellSession
    $ sudo userdel nixbld
    $ sudo groupdel nixbld
    ```

    If you do not wish to keep the Nix package manager installed either,
    run something like `sudo rm -rv ~/.nix-* /nix` and remove the line
    that the Nix installer added to your `~/.profile`.

1.  ::: {.note}
    The following steps are only for installing NixOS in place using
    `NIXOS_LUSTRATE`:
    :::

    Generate your NixOS configuration:

    ```ShellSession
    $ sudo `which nixos-generate-config`
    ```

    Note that this will place the generated configuration files in
    `/etc/nixos`. You'll probably want to edit the configuration files.
    Refer to the `nixos-generate-config` step in
    [](#sec-installation) for more information.

    ::: {.note}
    On [UEFI](https://en.wikipedia.org/wiki/UEFI) systems, check that your `/etc/nixos/hardware-configuration.nix` did the right thing with the [EFI System Partition](https://en.wikipedia.org/wiki/EFI_system_partition).
    In NixOS, by default, both [systemd-boot](https://systemd.io/BOOT/) and [grub](https://www.gnu.org/software/grub/index.html) expect it to be mounted on `/boot`.
    However, the configuration generator bases its [](#opt-fileSystems) configuration on the current mount points at the time it is run.
    If the current system and NixOS's bootloader configuration don't agree on where the [EFI System Partition](https://en.wikipedia.org/wiki/EFI_system_partition) is to be mounted, you'll need to manually alter the mount point in `hardware-configuration.nix` before building the system closure.
    :::

    ::: {.note}
    The lustrate process will not work if the [](#opt-boot.initrd.systemd.enable) option is set to `true`.
    If you want to use this option, wait until after the first boot into the NixOS system to enable it and rebuild.
    :::

    You'll likely want to set a root password for your first boot using
    the configuration files because you won't have a chance to enter a
    password until after you reboot. You can initialize the root password
    to an empty one with this line: (and of course don't forget to set
    one once you've rebooted or to lock the account with
    `sudo passwd -l root` if you use `sudo`)

    ```nix
    {
      users.users.root.initialHashedPassword = "";
    }
    ```

1.  Build the NixOS closure and install it in the `system` profile:

    ```ShellSession
    $ nix-env -p /nix/var/nix/profiles/system -f '<nixpkgs/nixos>' -I nixos-config=/etc/nixos/configuration.nix -iA system
    ```

1.  Change ownership of the `/nix` tree to root (since your Nix install