--- title: "Upgrading your operating system" description: "Find out how to upgrade your end of life operating system" url: https://docs.ovhcloud.com/en/guides/public-cloud/compute/upgrading-operating-system lang: en lastUpdated: 2026-06-23 --- # Upgrading your operating system ## Objective This tutorial will provide you with the steps to upgrade an end of life operating system to a new version. :::danger Warning: As with any major release upgrade of an operating system there is a risk of failure, data loss or broken software configuration. Therefore, OVHcloud strongly recommends [backing up your instance](/en/guides/public-cloud/compute/save-an-instance.md) and conducting extensive testing on your applications to make sure they work on the new operating system version prior to following this tutorial. ::: :::info To avoid problems mentioned above, it is recommended to install a new server with the new operating system you are upgrading to and migrate the data instead. You may still need to review differences in your application, but the operating system will likely have greater stability. ::: ## Requirements - [Administrative access](/en/guides/public-cloud/compute/getting-started.md#connect-instance) to the server - [Backup](/en/guides/public-cloud/compute/save-an-instance.md) must be taken before starting ## Instructions ### Debian Before starting with the major release upgrade, make sure that you update to the latest versions of all packages installed on the current release: ```bash $ sudo apt-get update $ sudo apt-get upgrade $ sudo apt-get full-upgrade ``` :::danger Warning: The following is an optional step. However, you must carefully review packages that are no longer needed on the system. Otherwise, the `sudo systemctl reboot` command might break the system. ::: ```bash $ sudo apt-get --purge autoremove ``` Some updates may require a reboot before proceeding with the upgrade: ```bash $ sudo systemctl reboot ``` After the reboot we will update the `/etc/apt/sources.list` to target the next release (in this case we go from Bullseye to Bookworm): ```bash $ sudo cp -v /etc/apt/sources.list /root/ $ sudo cp -rv /etc/apt/sources.list.d/ /root/ $ sudo sed -i 's/bullseye/bookworm/g' /etc/apt/sources.list $ sudo sed -i 's/bullseye\/updates/bookworm-security/g' /etc/apt/sources.list ``` Now that the latest release is set as target, perform the upgrade and finally initiate a reboot: :::info You may have popups asking you about restarting services. Answer them yes. ::: ```bash $ sudo apt-get update $ sudo apt-get upgrade $ sudo apt-get full-upgrade $ sudo systemctl reboot ``` Verify the upgrade has worked: ```bash $ uname -r $ lsb_release -a ``` ### Ubuntu Before starting with the major release upgrade, make sure that you update to the latest versions of all packages installed on the current release: ```bash $ sudo apt-get update ``` Next, you must upgrade your installed packages to their latest versions: ```bash $ sudo apt-get upgrade -y ``` Once it has finished, run `dist-upgrade` to apply any remaining upgrades: ```bash $ sudo apt-get dist-upgrade -y ``` Finally, you are now ready for the major release upgrade. Ubuntu provides a tool called `do-release-upgrade` that makes the upgrade safer and easier: ```bash $ sudo do-release-upgrade ``` Follow the instructions which will mainly consist of confirming you wish to proceed with specific actions. Please note: 1. You could be asked by the tool to restart your server first before doing the upgrade. To do this, just type `reboot` and press enter. 2. You will be advised that doing this over an SSH connection is not recommended. Since there is no physical access to the server, SSH is the primary way to access your server. Ubuntu will start a new SSH service on another port so that in case of failure you still have another access. Furthermore, you will still be able to access the server through the console if you are completely locked out by SSH. 3. During the upgrade, you may be asked to confirm the removal of packages that are no longer being supported. You need to double check this has no impact on your applications before continuing. Once the upgrade has completed, the server will reboot itself and you will lose connection until it boots up again. A few minutes later you should be able to log in and see a message similar to the following (the version will be the next available version compared to your previous version): ```bash $ Welcome to Ubuntu 24.04.4 LTS (GNU/Linux 6.8.0-124-generic x86_64) ``` :::info The new version will not be reflected on the OVHcloud Control Panel / API and on the Horizon / OpenStack API when you upgrade the operating system instead of reinstalling it. ::: Now verify if your applications are working as expected. In case there are issues, we recommend [restoring your backup](/en/guides/public-cloud/compute/create-restore-a-virtual-server-with-a-backup.md) that was taken prior to the upgrade. ### Fedora Before starting the major release upgrade, ensure that all installed packages are updated to the latest versions on the current release. Run the following command: ```bash $ sudo dnf upgrade --refresh ``` Now reboot the server: ```bash $ sudo reboot ``` Once the server is rebooted, install the upgrade package: ```bash $ sudo dnf install dnf-plugin-system-upgrade ``` Now that you have the required package, you can perform the upgrade. System upgrades are only officially supported and tested over 2 releases at most (e.g. from 42 to 44). In this example we will upgrade from Fedora 42 to 43: ```bash $ sudo dnf system-upgrade download --releasever=33 $ sudo dnf system-upgrade reboot ``` Once the version is downloaded and the upgrade process has been initiated, the server will reboot to complete the upgrade. It may take a while before you can connect again to the server as the upgrade takes a while to be completed. Verify if your applications are working as expected. In case there are issues, we recommend [restoring your backup](/en/guides/public-cloud/compute/create-restore-a-virtual-server-with-a-backup.md) that was taken prior to the upgrade. :::info If you encounter any issues, you may find answers to your questions on the [Fedora Docs](https://docs.fedoraproject.org/en-US/quick-docs/dnf-system-upgrade/). ::: ## Go further Join our [community of users](https://community.ovhcloud.com/).