Skip to main content
Zirconium uses bootc for atomic, image-based updates. Updates are downloaded and staged in the background, then applied on the next reboot.

​
How bootc updates work

bootc (Boot Container) is an image-based update system that treats your operating system as an immutable container image:
  • Your system boots from a container image stored in /usr/lib/bootc
  • Updates download new container images without modifying your running system
  • Each update creates a new deployment that you boot into after restarting
  • Previous deployments are kept for easy rollback
  • All changes are atomic - either fully applied or not at all
Zirconium is configured to automatically stage updates weekly. Updates are downloaded and prepared but won’t take effect until you reboot.

​
Checking for updates

To check if updates are available: 
bootc status
This command shows:
  • Your current deployment version
  • Available updates
  • Staged updates (if any)
  • Previously booted deployments
To manually check for new updates: 
sudo bootc upgrade --check

​
Applying updates

Zirconium automatically checks for updates weekly using a systemd timer (bootc-fetch-apply-updates.timer). Updates are staged automatically but require a reboot to take effect.
1

Manually update your system

To manually fetch and stage updates:
sudo bootc upgrade
This downloads the latest Zirconium image and stages it for the next boot.
2

Reboot to apply

After updates are staged, reboot your system:
systemctl reboot
Your system will boot into the new deployment with all updates applied.
Check systemctl status bootc-fetch-apply-updates.service to see when the last automatic update check ran.

​
Rolling back updates

If an update causes issues, you can easily roll back to a previous deployment.
1

List available deployments

View all bootable deployments:
bootc status
Look for the “Staged” and “Rollback” deployments in the output.
2

Roll back at boot

During system boot, the GRUB bootloader shows a menu. Select the previous deployment to boot into the older version.
3

Make rollback permanent

If you boot into a previous deployment and want to make it permanent:
sudo bootc rollback
This sets the previous deployment as default for future boots.
Deployments are automatically cleaned up to save disk space. If you need to keep a specific deployment, pin it before cleanup runs.

​
Update frequency and release channels

Zirconium follows a continuous delivery model:
  • Update frequency: Automatic checks run weekly (configured in bootc-fetch-apply-updates.timer)
  • Release channel: latest - receives all updates as they’re published
  • Container registry: ghcr.io/zirconium-dev/zirconium:latest (or zirconium-nvidia:latest)

​
Understanding the update policy

Zirconium is configured with AutomaticUpdatePolicy=stage in /etc/rpm-ostreed.conf, which means:
  • Updates are automatically downloaded and staged
  • Updates are not automatically applied (no automatic reboots)
  • You control when to reboot and apply updates

​
Checking which image you’re running

To see your current Zirconium image: 
bootc status
Look for the image reference, which shows:
  • Base image: ghcr.io/zirconium-dev/zirconium:latest or zirconium-nvidia:latest
  • Image digest: A unique hash identifying the exact build
  • Build date: When the image was created

​
Switching between standard and NVIDIA variants

If you need to switch between the standard and NVIDIA images: 
# Switch to NVIDIA variant
sudo bootc switch ghcr.io/zirconium-dev/zirconium-nvidia:latest

# Switch to standard variant
sudo bootc switch ghcr.io/zirconium-dev/zirconium:latest
Then reboot to apply the change.
Switching images requires downloading the entire image. Ensure you have a stable internet connection and sufficient disk space.