.. _multi-boot:

Multi-boot Clear Linux with other operating systems
###################################################

|CLOSIA| uses the Systemd-Boot boot loader, which does not support multi-
booting without manual manipulation. This tutorial shows how to configure the
|CL| boot loader to work with other :abbr:`OSes (operating systems)`.

Process overview
****************

The process to install other operating systems for a multi-booting computer is
described below. Install |CL| first, then install other operating systems in
any order.

#. Install |CL| first with a EFI partition large enough to store the kernels
   of other operating systems and their initrds, in the case of Linux
   distributions.

#. Install the next operating system without creating its own EFI
   partition.

#. Boot into the newly installed operating system.

#. For Linux distributions, copy its kernel and `initrd` to the |CL| EFI
   partition. This step is not needed for Windows\*.

#. Add an entry for the newly installed operating system in the
   Systemd-Boot menu.

#. Make Systemd-Boot the default boot loader.

#. Repeat the previous steps to install each additional operating system.

If you update any installed operating systems, be aware that:

*  The default boot loader may change from |CL| Systemd-Boot. Perform the
   steps in :ref:`multi-boot-restore-bl`.

*  Linux kernels or `initrd` images may change. Keep their corresponding Systemd-Boot
   :file:`/boot/efi/loader/entries/*.conf` files up-to-date.

This process is not guaranteed to work with all Linux distributions and all
their versions. The next section lists the OSes that we tested.


Tested operating systems
************************

The following operating systems were tested on an Intel® NUC6i7KYK with 32GB
RAM and a 360GB SSD. Table 1 lists the information specific to the
installation of the tested operating systems.

.. csv-table:: Table 1: OS specific installation information
   :header: # , OS, Version, Partition Size [#]_, Swap Size [#]_, EFI Partition Size [#]_, Download Link

   1,Clear Linux,16140,50 GB,8 GB,1 GB,https://download.clearlinux.org/releases/16140/clear/
   2,Windows,Server 2016,50 GB,N/A,Shared with #1,https://www.microsoft.com/en-us/cloud-platform/windows-server
   3,Red Hat\*,Server 7.4 Beta,45 GB,Shared with #1,Shared with #1,https://access.redhat.com/downloads/
   4,SUSE\*,Server 12 SP2,45 GB,Shared with #1,Shared with #1,https://www.suse.com/download-linux/
   5,Ubuntu\*,16.04.02 LTS Desktop,40 GB,Shared with #1,Shared with #1,https://www.ubuntu.com/download/desktop
   6,Linux Mint\*,18.1 *Serena* MATE,40 GB,Shared with #1,Shared with #1,https://linuxmint.com/edition.php?id=228

Table notes:

.. [#] Configure the partition size as desired.


.. [#] To save disk space, share a single swap partition between
   multiple Linux installations. Swap size was determined using these
   `recommended swap partition sizes`_.


.. [#] The EFI partition holds the kernel and boot information for |CL| and
   other operating systems. The partition size is dependent on the number
   of operating systems to be installed. In general, allocate about 100 MB
   per operating system. For this tutorial, we used 1 GB.



.. _multi-boot-detail-proc:

Detailed procedures
*******************

*  :ref:`multi-boot-cl` (below)

.. toctree::
   :maxdepth: 2

   multi-boot-win
   multi-boot-rhel
   multi-boot-sles
   multi-boot-ubuntu
   multi-boot-mint
   multi-boot-restore-bl


.. _multi-boot-cl:

Install Clear Linux OS
**********************

Navigation tips for text-based installation interfaces:

*  Use the :kbd:`Up Arrow` and :kbd:`Down Arrow` keys to move between
   the options on the screen.

*  Use the :kbd:`Space` to select or highlight an option.

*  Press :kbd:`Enter` to activate the selected option and to move ahead.

Installation details
====================

#. Create a bootable USB drive of the |CL| installer using one of the methods
   below.

   * :ref:`bootable-usb-linux`
   * :ref:`bootable-usb-mac`
   * :ref:`bootable-usb-windows`

#. Start the |CL| installer and follow the prompts.

#. On the :guilabel:`Choose Installation Type` screen, choose
   :guilabel:`Manual (Advanced)`, as shown in Figure 1.

   .. figure:: figures/multi-boot-01.png

      Figure 1: |CL| installer: Choose installation type screen.

#. On the :guilabel:`Choose partitioning method` screen, choose
   :guilabel:`Manually configure mounts and partitions`, as shown in
   Figure 2.

   .. figure:: figures/multi-boot-02.png

      Figure 2: |CL|: Choose partitioning method.

#. Select the drive, in this case :file:`/dev/sda`, and press :kbd:`Enter` to
   go into the `cgdisk` partitioning tool. See Figure 3.

   .. figure:: figures/multi-boot-03.png

   Figure 3: |CL|: Choose drive to partition.

#. Create a new root partition.

   #. Select :guilabel:`New`, as shown in Figure 4.

      .. _multi-boot-04:

      .. figure:: figures/multi-boot-04.png

         Figure 4: |CL|: Create new partition.

   #. Accept the default first sector.

   #. Specify the desired size of the partition. For this example, we
      specified *50 GB*. See Figure 5.

      .. figure:: figures/multi-boot-05.png

         Figure 5: |CL|: New partition size.

   #. Set the partition type to :guilabel:`8300 (Linux filesystem)`, as shown
      in Figure 6.

      .. figure:: figures/multi-boot-06.png

         Figure 6: |CL|: Set partition type.

   #. Name the partition :file:`CL-root`. This name makes it easier to
      identify later. See Figure 7.

      .. figure:: figures/multi-boot-07.png

         Figure 7: |CL|: Name partition.

#. Create a new swap partition as shown in Figure 8.

   .. figure:: figures/multi-boot-08.png

      Figure 8: |CL|: Create swap partition.

   #. Select the *free space* partition located at the bottom of the column.

   #. Select :guilabel:`New`. See :ref:`Figure 4<multi-boot-04>`.

   #. Accept the default first sector.

   #. Specify the desired size of the swap partition. For this example, we
      used 8 GB. See the `recommended swap partition sizes`_ for guidance.

   #. Set the partition type to :guilabel:`8200 (Linux swap)`.

   #. Name the partition :file:`CL-swap`.

#. Create a new EFI partition as shown in Figure 9.

   .. figure:: figures/multi-boot-09.png

      Figure 9: |CL|: Create EFI partition.

   #. In the :guilabel:`Partition Type` column, select :guilabel:`free space`
      located at the bottom of the column.

   #. Select :guilabel:`New`. See :ref:`Figure 4<multi-boot-04>`.

   #. Accept the default first sector.

   #. Specify the desired size of the partition. For this example, we used
      1024 MB. This partition will hold |CL|, the kernels of the other
      operating systems, and their boot information. Its size depends on the
      number of installed operating systems. In general, allocate about 100 MB
      per operating system. For this example, we used 1024 MB.

   #. Set the partition type to :guilabel:`ef00 (EFI partition)`.

   #. Name the partition :file:`CL-EFI`.

#. Select :guilabel:`Write` to apply the new partition table.

#. Select :guilabel:`Quit` to exit the `cgdisk` tool.

#. On the :guilabel:`Set mount points` screen, specify the mount points and
   format settings as shown in Figure 10.

   .. figure:: figures/multi-boot-10.png

      Figure 10: |CL|: Set mount points.

#. On the :guilabel:`User configuration` screen, select
   :guilabel:`Create an administrative user`, as shown in Figure 11.

   .. figure:: figures/multi-boot-11.png

      Figure 11: |CL|: User configuration.

#. Select :guilabel:`Add user to sudoers?`, as shown in Figure 12.

   .. figure:: figures/multi-boot-12.png

      Figure 12: |CL|: Add user as sudoer.

#. Follow the remaining prompts to complete the installation and finish
   the out-of-box-experience for |CL|.

#. Log in.

#. Add a Systemd-Boot timeout period or Systemd-Boot will not present the
   boot menu of available OSes to choose from and will always boot |CL|.

   .. code-block:: bash

      sudo clr-boot-manager set-timeout 20

      sudo clr-boot-manager update

#. Reboot.

If you want to install other OSes, refer to :ref:`multi-boot-detail-proc`.

.. _recommended swap partition sizes:
   https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Deployment_Guide/ch-swapspace.html
