Booting a Live ISO Image from Network

In KIWI, live ISO images can be configured to boot via PXE. This functionality requires a network boot server setup on the system. Details how to setup such a server can be found in Setting Up a Network Boot Server.

After the live ISO was built as shown in Build an ISO Hybrid Live Image, the following configuration steps are required to boot from the network:

  1. Extract initrd/kernel From Live ISO

    The PXE boot process loads the configured kernel and initrd from the PXE server. For this reason, those two files must be extracted from the live ISO image and copied to the PXE server as follows:

    $ mount LimeJeOS-Leap-42.3.x86_64-1.42.3.iso /mnt
    $ cp /mnt/boot/x86_64/loader/initrd /srv/tftpboot/boot/initrd
    $ cp /mnt/boot/x86_64/loader/linux /srv/tftpboot/boot/linux
    $ umount /mnt
    

    Note

    This step must be repeated with any new build of the live ISO image

  2. Export Live ISO To The Network

    Access to the live ISO file is implemented using the AoE protocol in KIWI. This requires the export of the live ISO file as remote block device which is typically done with the vblade toolkit. Install the following package on the system which is expected to export the live ISO image:

    $ zypper in vblade
    

    Note

    Not all versions of AoE are compatible with any kernel. This means the kernel on the system exporting the live ISO image must provide a compatible aoe kernel module compared to the kernel used in the live ISO image.

    Once done, export the live ISO image as follows:

    $ vbladed 0 1 INTERFACE LimeJeOS-Leap-42.3.x86_64-1.42.3.iso
    

    The above command exports the given ISO file as a block storage device to the network of the given INTERFACE. On any machine except the one exporting the file, it will appear as /dev/etherd/e0.1 once the aoe kernel module was loaded. The two numbers, 0 and 1 in the above example, classifies a major and minor number which is used in the device node name on the reading side, in this case e0.1. The numbers given at export time must match the AOEINTERFACE name as described in the next step.

    Note

    Only machines in the same network of the given INTERFACE can see the exported live ISO image. If virtual machines are the target to boot the live ISO image they could all be connected through a bridge. In this case INTERFACE is the bridge device. The availability scope of the live ISO image on the network is in general not influenced by KIWI and is a task for the network administrators.

  3. Setup live ISO boot entry in PXE configuration

    Edit the file /srv/tftpboot/pxelinux.cfg/default and create a boot entry of the form:

    LABEL Live-Boot
        kernel boot/linux
        append initrd=boot/initrd rd.kiwi.live.pxe root=live:AOEINTERFACE=e0.1
    
    • The boot parameter rd.kiwi.live.pxe tells the KIWI boot process to setup the network and to load the required aoe kernel module.
    • The boot parameter root=live:AOEINTERFACE=e0.1 specifies the interface name as it was exported by the vbladed command from the last step. Currently only AoE (Ata Over Ethernet) is supported.
  4. Boot from the Network

    Within the network which has access to the PXE server and the exported live ISO image, any network client can now boot the live system. A test based on QEMU is done as follows:

    $ qemu -boot n