Red Hat Summit Red Hat SummitSupportKonsoleEntwicklerDemo startenKontakt

Dieser Inhalt ist in der von Ihnen ausgewählten Sprache nicht verfügbar.

Chapter 11. Updating the boot loader on RHCOS nodes using bootupd

To update the boot loader on RHCOS nodes using bootupd, you must either run the bootupctl update command on RHCOS machines manually or provide a machine config with a systemd unit.

Unlike grubby or other boot loader tools, bootupd does not manage kernel space configuration such as passing kernel arguments. To configure kernel arguments, see Adding kernel arguments to nodes.

Note

You can use bootupd to update the boot loader to protect against the BootHole vulnerability.

11.1. Updating the boot loader manually
Link kopieren

You can manually inspect the status of the system and update the boot loader by using the bootupctl command-line tool.

  1. Inspect the system status: 

    # bootupctl status
    Copy to Clipboard Toggle word wrap

    Example output for x86_64

    Component EFI
  Installed: grub2-efi-x64-1:2.04-31.el8_4.1.x86_64,shim-x64-15-8.el8_1.x86_64
  Update: At latest version
    Copy to Clipboard Toggle word wrap

    Example output for aarch64

    Component EFI
  Installed: grub2-efi-aa64-1:2.02-99.el8_4.1.aarch64,shim-aa64-15.4-2.el8_1.aarch64
  Update: At latest version
    Copy to Clipboard Toggle word wrap

  1. OpenShift Container Platform clusters initially installed on version 4.4 and older require an explicit adoption phase.

    If the system status is Adoptable, perform the adoption: 

    # bootupctl adopt-and-update
    Copy to Clipboard Toggle word wrap

    Example output

    Updated: grub2-efi-x64-1:2.04-31.el8_4.1.x86_64,shim-x64-15-8.el8_1.x86_64
    Copy to Clipboard Toggle word wrap

  2. If an update is available, apply the update so that the changes take effect on the next reboot: 

    # bootupctl update
    Copy to Clipboard Toggle word wrap

    Example output

    Updated: grub2-efi-x64-1:2.04-31.el8_4.1.x86_64,shim-x64-15-8.el8_1.x86_64
    Copy to Clipboard Toggle word wrap

11.2. Updating the bootloader automatically via a machine config
Link kopieren

Another way to automatically update the boot loader with bootupd is to create a systemd service unit that will update the boot loader as needed on every boot. This unit will run the bootupctl update command during the boot process and will be installed on the nodes via a machine config.

Note

This configuration is not enabled by default as unexpected interruptions of the update operation may lead to unbootable nodes. If you enable this configuration, make sure to avoid interrupting nodes during the boot process while the bootloader update is in progress. The boot loader update operation generally completes quickly thus the risk is low.

  1. Create a Butane config file, 99-worker-bootupctl-update.bu, including the contents of the bootupctl-update.service systemd unit.

    Note

    The Butane version you specify in the config file should match the OpenShift Container Platform version and always ends in 0. For example, 4.12.0. See "Creating machine configs with Butane" for information about Butane.

    Example output

    variant: openshift
version: 4.12.0
metadata:
  name: 99-worker-chrony
    1 
    
  labels:
    machineconfiguration.openshift.io/role: worker
    2 
    
systemd:
  units:
  - name: bootupctl-update.service
    enabled: true
    contents: |
      [Unit]
      Description=Bootupd automatic update

      [Service]
      ExecStart=/usr/bin/bootupctl update
      RemainAfterExit=yes

      [Install]
      WantedBy=multi-user.target
    Copy to Clipboard Toggle word wrap

    1 2
    On control plane nodes, substitute master for worker in both of these locations.

  2. Use Butane to generate a MachineConfig object file, 99-worker-bootupctl-update.yaml, containing the configuration to be delivered to the nodes: 

    $ butane 99-worker-bootupctl-update.bu -o 99-worker-bootupctl-update.yaml
    Copy to Clipboard Toggle word wrap

  3. Apply the configurations in one of two ways:

    • If the cluster is not running yet, after you generate manifest files, add the MachineConfig object file to the <installation_directory>/openshift directory, and then continue to create the cluster.

    • If the cluster is already running, apply the file: 

      $ oc apply -f ./99-worker-bootupctl-update.yaml
      Copy to Clipboard Toggle word wrap
Nach oben
Red Hat logoGithubredditYoutubeTwitter

Lernen

Testen, kaufen und verkaufen

Communitys

Über Red Hat Dokumentation

Wir helfen Red Hat Benutzern, mit unseren Produkten und Diensten innovativ zu sein und ihre Ziele zu erreichen – mit Inhalten, denen sie vertrauen können. Entdecken Sie unsere neuesten Updates.

Mehr Inklusion in Open Source

Red Hat hat sich verpflichtet, problematische Sprache in unserem Code, unserer Dokumentation und unseren Web-Eigenschaften zu ersetzen. Weitere Einzelheiten finden Sie in Red Hat Blog.

Über Red Hat

Wir liefern gehärtete Lösungen, die es Unternehmen leichter machen, plattform- und umgebungsübergreifend zu arbeiten, vom zentralen Rechenzentrum bis zum Netzwerkrand.

Theme

© 2025 Red Hat