Automated install

    Unattended installation requires what is called an answer file, often spelled answerfile.

    It is an XML file that contains the answers to questions the installer would ask during a manual installation.


    Here's an example:

    <?xml version="1.0"?>
    <installation srtype="ext">
        <primary-disk>sda</primary-disk>
        <guest-disk>sdb</guest-disk>
        <guest-disk>sdc</guest-disk>
        <keymap>us</keymap>
        <root-password>mypassword</root-password>
        <source type="url">http://pxehost.example.com/xcp-ng/</source>
        <post-install-script type="url">
            http://pxehost.example.com/myscripts/post-install-script
        </post-install-script>
        <admin-interface name="eth0" proto="dhcp" />
        <timezone>Europe/Paris</timezone>
    </installation>

    TIP

    Via PXE

    Follow the previous section on Network boot (PXE) and add options to that will fetch and use an answer file.


    PXE unattended install - BIOS boot

    Add answerfile=http://your_server/path/to/answerfile.xml install to the parameters passed to vmlinuz (the linux kernel of the installer).


    Example:

    menuentry "XCP-ng Install (serial)" {
    multiboot2 /EFI/xcp-ng/xen.gz dom0_mem=2048M,max:2048M watchdog dom0_max_vcpus=4 com1=115200,8n1 console=com1,vga
    module2 /EFI/xcp-ng/vmlinuz console=hvc0 console=tty0 answerfile_device=eth0 answerfile=http://your_server/path/to/answerfile.xml install
    module2 /EFI/xcp-ng/install.img
}


    Unattended installation with a custom ISO image

    You may build a custom installation image that will automatically install XCP-ng. The answerfile can either be downloaded by the installer or embedded in the image itself.


    Unattended installation ISO with remote config

    If you can't or don't want to setup PXE but can still serve a file (the answerfile) from a server that will be available to the hosts during installation, you can create an automated installation image that will fetch its configuration from the network.


    1. Prepare an answerfile and make it available from a local HTTP server
    3. Modify the boot configuration to use the remote answerfile

    • For BIOS boot, edit /boot/isolinux/isolinux.cfg.
      • Locate the install boot entry, which should look like this:
      LABEL install
    KERNEL mboot.c32
    APPEND /boot/xen.gz dom0_max_vcpus=1-16 dom0_mem=max:8192M com1=115200,8n1 console=com1,vga --- /boot/vmlinuz console=hvc0 console=tty0 --- /install.img
      • Append answerfile=http://your_server/path/to/answerfile.xml install to the parameters passed to vmlinuz, before the last ---:
      LABEL install
    KERNEL mboot.c32
    APPEND /boot/xen.gz dom0_max_vcpus=1-16 dom0_mem=max:8192M com1=115200,8n1 console=com1,vga --- /boot/vmlinuz console=hvc0 console=tty0 answerfile=http://your_server/path/to/answerfile.xml install --- /install.img
    • For UEFI boot edit /EFI/xenserver/grub.cfg (and /EFI/xenserver/grub-usb.cfg for USB installation).
      • Locate the install menuentry, which should look like this:
      menuentry "install" {
    multiboot2 /boot/xen.gz dom0_max_vcpus=1-16 dom0_mem=max:8192M com1=115200,8n1 console=com1,vga
    module2 /boot/vmlinuz console=hvc0 console=tty0
    module2 /install.img
}
      • Append answerfile=http://your_server/path/to/answerfile.xml install to the parameters passed to vmlinuz, in the line that starts with module2 /boot/vmlinuz:
      menuentry "install" {
    multiboot2 /boot/xen.gz dom0_max_vcpus=1-16 dom0_mem=max:8192M com1=115200,8n1 console=com1,vga
    module2 /boot/vmlinuz console=hvc0 console=tty0 answerfile=http://your_server/path/to/answerfile.xml install
    module2 /install.img
}
      • Append answerfile=file:///answerfile.xml install to the parameters passed to vmlinuz, in the line that starts with module2 /boot/vmlinuz:
      menuentry "install" {
    multiboot2 /boot/xen.gz dom0_max_vcpus=1-16 dom0_mem=max:8192M com1=115200,8n1 console=com1,vga
    module2 /boot/vmlinuz console=hvc0 console=tty0 answerfile=file:///answerfile.xml install
    module2 /install.img
}

    4. Extract install.img

    5. Add your answerfile

    cp answerfile.xml "$WORK_DIR/install/answerfile.xml"

    6. Build a new install.img with your changes

    7. Build a new ISO with your changes


    Your ISO is ready for installation.

    Software RAID in answerfile

    For an automated install using an answer file, software raid can be enabled as follows:

    <?xml version="1.0"?>
<installation mode="fresh" srtype="lvm">
    <raid device="md127">
        <disk>sda</disk>
        <disk>sdb</disk>
    </raid>
    <primary-disk>md127</primary-disk>
    <keymap>us</keymap>
    <source type="url">https://xcp-ng.org/install/</source>
    <admin-interface name="eth0" proto="dhcp" />
    <timezone>Europe/London</timezone>
    <root-password>secret</root-password>
</installation>


    As an improvement and to delay the md resync (increasing install speed by about 500% on certain drives), we can use the following in the answer file:

    <script stage="installation-start" type="url">http://your-server/noresync.sh</script>


    The noresync.sh script would do something like this:

    #!/bin/sh
echo 0 > /proc/sys/dev/raid/speed_limit_max
echo 0 > /proc/sys/dev/raid/speed_limit_min

    Upon server reboot, normal md resync will take place.

    Published