Virtualization

Use the following command to install a VirtualBox extension pack on a server or other headless machine:

sudo vboxmanage extpack install [filename]

for example

sudo vboxmanage extpack install Oracle_VM_VirtualBox_Extension_Pack-7.0.8.vbox-extpack

The following sequence allows you to enter the UEFI setup and set the screen size. It does not work for VMs running BIOS!

1. Open the VM’s console
2. Start the VM
3. Immediately start pressing F2 repeatedly until you see the UEFI setup screen:
4. Enter the Device Manager
5. Enter OVMF Platform Configuration and select the screen resolution
6. Exit by pressing ESC and select Y to save the changes. Continue pressing ESC until you are at the start screen.
7. Now select Reset and wait for the OS to boot. You need to select Reset because the change will only be effective after the next complete reboot.

For many xe commands on XCP-NG you have to use a host-uuid=... parameter.

In order to find out your Host UUID, use

xe host-list

Example:

[03:19 virt01-xcpng ~]# xe host-list
uuid ( RO)                : 71739b18-2999-4794-a024-87d5d26215d1
          name-label ( RW): virt01-xcpng
    name-description ( RW): Default install

In this example, the Host UUID of the only host is 71739b18-2999-4794-a024-87d5d26215d1.

Using CoreOS? See this post instead!

First, insert the guest-tools.iso supplied with XCP-NG into the DVD drive of the virtual machine.

Then run these commands. Note that this will reboot the machine after it finished

sudo mount -o ro /dev/sr0 /mnt/
cd /mnt/Linux
sudo ./install.sh -n
sudo reboot

After the VM reboots, XCP-NG should detect the management agent.

Please eject the guest tools medium from the machine after the reboot! Sometimes unneccessarily mounted media cause issues.

This is the Ignition config that I use to bring up my Fedora CoreOS instance on a VM on my XCP-NG server:

{
  "ignition": {
    "version": "3.2.0"
  },
  "passwd": {
    "users": [
      {
        "groups": [
          "sudo",
          "docker"
        ],
        "name": "uli",
        "sshAuthorizedKeys": [
          "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQDpvDSxIwnyMCFtIPRQmPUV6hh9lBJUR0Yo7ki+0Vxs+kcCHGjtcgDzcaHginj1zvy7nGwmcuGi5w83eKoANjK5CzpFT4vJeiXqtGllh0w+B5s6tbSsD0Wv3SC9Xc4NihjVjLU5gEyYmfs/sTpiow225Al9UVYeg1SzFr1I3oSSuw== [email protected]"
        ]
      }
    ]
  },
  "storage": {
    "files": [
      {
        "path": "/etc/hostname",
        "contents": {
          "source": "data:,coreos-test%0A"
        },
        "mode": 420
      },
      {
        "path": "/etc/profile.d/systemd-pager.sh",
        "contents": {
          "source": "data:,%23%20Tell%20systemd%20to%20not%20use%20a%20pager%20when%20printing%20information%0Aexport%20SYSTEMD_PAGER%3Dcat%0A"
        },
        "mode": 420
      },
      {
        "path": "/etc/sysctl.d/20-silence-audit.conf",
        "contents": {
          "source": "data:,%23%20Raise%20console%20message%20logging%20level%20from%20DEBUG%20(7)%20to%20WARNING%20(4)%0A%23%20to%20hide%20audit%20messages%20from%20the%20interactive%20console%0Akernel.printk%3D4"
        },
        "mode": 420
      }
    ]
  },
  "systemd": {
    "units": [
      {
        "enabled": true,
        "name": "docker.service"
      },
      {
        "enabled": true,
        "name": "containerd.service"
      },
      {
        "dropins": [
          {
            "contents": "[Service]\n# Override Execstart in main unit\nExecStart=\n# Add new Execstart with `-` prefix to ignore failure\nExecStart=-/usr/sbin/agetty --autologin core --noclear %I $TERM\nTTYVTDisallocate=no\n",
            "name": "autologin-core.conf"
          }
        ],
        "name": "[email protected]"
      }
    ]
  }
}

Which is build from this YAML:

variant: fcos
version: 1.2.0
passwd:
  users:
    - name: uli
      groups:
        - "sudo"
        - "docker"
      ssh_authorized_keys:
        - "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQDpvDSxIwnyMCFtIPRQmPUV6hh9lBJUR0Yo7ki+0Vxs+kcCHGjtcgDzcaHginj1zvy7nGwmcuGi5w83eKoANjK5CzpFT4vJeiXqtGllh0w+B5s6tbSsD0Wv3SC9Xc4NihjVjLU5gEyYmfs/sTpiow225Al9UVYeg1SzFr1I3oSSuw== [email protected]"

systemd:
  units:
    - name: docker.service
      enabled: true

    - name: containerd.service
      enabled: true
    - name: [email protected]
      dropins:
      - name: autologin-core.conf
        contents: |
          [Service]
          # Override Execstart in main unit
          ExecStart=
          # Add new Execstart with `-` prefix to ignore failure
          ExecStart=-/usr/sbin/agetty --autologin core --noclear %I $TERM
          TTYVTDisallocate=no
storage:
  files:
    - path: /etc/hostname
      mode: 0644
      contents:
        inline: |
          coreos-test
    - path: /etc/profile.d/systemd-pager.sh
      mode: 0644
      contents:
        inline: |
          # Tell systemd to not use a pager when printing information
          export SYSTEMD_PAGER=cat
    - path: /etc/sysctl.d/20-silence-audit.conf
      mode: 0644
      contents:
        inline: |
          # Raise console message logging level from DEBUG (7) to WARNING (4)
          # to hide audit messages from the interactive console
          kernel.printk=4

using

fcct --pretty --strict ignition.yml --output ignition.ign

or TechOverflow’s online transpiler tool.

Install using:

sudo coreos-installer install /dev/xvda --copy-network --ignition-url https://mydomain.com/ignition.ign

Features:

• DHCP on all network interfaces
• TTY on the screen
• No password – remember to replace the SSH key by your key!

Important note: While installing the Xen utilities using the CD ISO still works, it is outdated and you should prefer installing it using the rpm package. See our post Fedora CoreOS: How to install Xen/XCP-NG guest utilities using rpm-ostree

First, insert the guest-tools.iso supplied with XCP-NG into the DVD drive of the virtual machine.

Then run this sequence of commands to install. Note that this will reboot the CoreOS instance!

curl -fsSL https://techoverflow.net/scripts/install-xenutils-coreos.sh | sudo bash /dev/stdin

This will run the following script:

sudo mount -o ro /dev/sr0 /mnt
sudo rpm-ostree install /mnt/Linux/*.x86_64.rpm
sudo cp -f /mnt/Linux/xen-vcpu-hotplug.rules /etc/udev/rules.d/
sudo cp -f /mnt/Linux/xe-linux-distribution.service /etc/systemd/system/
sudo sed 's/share\/oem\/xs/sbin/g' -i /etc/systemd/system/xe-linux-distribution.service
sudo systemctl daemon-reload
sudo systemctl enable /etc/systemd/system/xe-linux-distribution.service
sudo umount /mnt
sudo systemctl reboot

After rebooting the VM, XCP-NG should detect the management agent.

Based on work by steniofilho on the Fedora Forum.

Please eject the guest tools medium from the machine after the reboot! Sometimes unneccessarily mounted media cause issues.

In order to list VMs on the command line, login to XCP-NG using SSH and run this command:

xe vm-list

Example output:

[16:51 virt01-xcpng ~]# xe vm-list
uuid ( RO)           : 56dc99f2-c617-f7a9-5712-a4c9df54229a
     name-label ( RW): VM 1
    power-state ( RO): running


uuid ( RO)           : 268d56ab-9672-0f45-69ae-efbc88380b21
     name-label ( RW): VM2
    power-state ( RO): running


uuid ( RO)           : 9b1a771f-fb84-8108-8e01-6dac0f957b19
     name-label ( RW): My VM 3
    power-state ( RO): running