How to Upgrade From Ubuntu 24.04 to Ubuntu 26.04
Ubuntu is a widely adopted open-source Linux distribution released on a predictable schedule, with Long Term Support (LTS) versions receiving security and maintenance updates for five years. Ubuntu 26.04 LTS, codenamed Resolute Raccoon, ships with the Linux 7.0 kernel, an updated set of default packages, and security improvements over Ubuntu 24.04. Upgrading an existing server carries forward your data and configurations to the newer release without requiring a fresh deployment.
This article explains how to upgrade a server from Ubuntu 24.04 LTS to Ubuntu 26.04 LTS. It covers verifying application compatibility, preparing the system, running the upgrade tool, testing the result, and resolving common post-upgrade issues.
Prerequisites
Before you begin, you need to:
Have access to an Ubuntu 24.04 server instance as a non-root user with sudo privileges.
Ensure at least 5 GB of free disk space is available. Run the command below to check.
console$ df -h
Output:
Filesystem Size Used Avail Use% Mounted on tmpfs 96M 2.4M 93M 3% /run /dev/vda2 23G 6.5G 16G 30% / tmpfs 476M 0 476M 0% /dev/shm tmpfs 5.0M 0 5.0M 0% /run/lock /dev/vda1 511M 6.1M 505M 2% /boot/efi tmpfs 96M 4.0K 96M 1% /run/user/0
Verify Application Compatibility
Some packages installed on Ubuntu 24.04 may not be compatible with Ubuntu 26.04, which can cause dependency conflicts or runtime errors after the upgrade. Auditing your installed software before starting reduces the chance of post-upgrade failures. Follow the steps below to export and review your package list.
Save a list of all installed packages to a file.
console$ sudo dpkg --get-selections > packages-list.txt
Browse the exported package list.
console$ cat packages-list.txt | more
Review the official Ubuntu 26.04 release notes to identify any known incompatible dependencies or removed packages.
Update System Packages
Upgrading all existing packages before starting the release upgrade minimizes the risk of conflicts introduced by outdated software. Follow the steps below to bring the system up to date and remove unnecessary packages.
Confirm the server is running Ubuntu 24.04.
console$ cat /etc/os-release
Update the package information index.
console$ sudo apt update
Upgrade all installed packages to their latest available versions.
console$ sudo apt upgrade -y
If the system displays the following kernel warning after upgrading, restart the server before continuing.
Pending kernel upgrade! Running kernel version: 6.8.0-107-generic Diagnostics: The currently running kernel version is not the expected kernel version 6.8.0-111-generic. Restarting the system to load the new kernel will not be handled automatically, so you should consider rebooting.console$ sudo reboot
Remove packages that are no longer needed.
console$ sudo apt autoremove -y
Clear the local package cache.
console$ sudo apt autoclean
Enable the Temporary SSH Port
The do-release-upgrade tool starts an auxiliary SSH daemon on port 1022 during the upgrade. This fallback connection allows you to reconnect if the primary SSH session drops mid-upgrade. Follow the steps below to open this port in the firewall before launching the upgrade.
Allow port
1022through UFW.console$ sudo ufw allow 1022/tcp
Reload UFW to activate the new rule.
console$ sudo ufw reload
Verify that port
1022appears in the active ruleset.console$ sudo ufw status
Output:
Status: active To Action From -- ------ ---- 22/tcp ALLOW Anywhere 1022/tcp ALLOW Anywhere 22/tcp (v6) ALLOW Anywhere (v6) 1022/tcp (v6) ALLOW Anywhere (v6)
Upgrade from Ubuntu 24.04 to 26.04
With the server prepared, launch the release upgrade tool to begin the transition to Ubuntu 26.04 LTS. The tool downloads updated packages, asks you to resolve configuration file conflicts, and restarts the server when the upgrade is complete. Follow the steps below to run the upgrade.
Launch the release upgrade tool.
console$ sudo do-release-upgrade -d
Enter
yand press Enter when prompted to confirm the upgrade to Ubuntu 26.04 LTS.Checking for a new Ubuntu release = Welcome to Ubuntu 26.04 LTS 'Resolute Raccoon' = The Ubuntu team is proud to announce Ubuntu 26.04 LTS 'Resolute Raccoon'. To see what's new in this release, visit: https://discourse.ubuntu.com/t/resolute-raccoon-release-notes Ubuntu is a Linux distribution for your desktop or server. It is fast and easy to install, it has regular releases, a tight selection of excellent applications installed by default, and almost any other software you can imagine available through the network. We hope you enjoy Ubuntu. == Feedback and helping == To help shape Ubuntu, look at the list of ways to participate at: https://documentation.ubuntu.com/project/community/contribute/ ... To sign up for future Ubuntu announcements, subscribe to Ubuntu's very low-volume announcement list: https://lists.ubuntu.com/mailman/listinfo/ubuntu-announce Continue [yN]Enter
yand press Enter to allow the upgrade tool to open an auxiliary SSH daemon on port1022.Reading cache Checking package manager Continue running under SSH? This session appears to be running under ssh. It is not recommended to perform a upgrade over ssh currently because in case of failure it is harder to recover. If you continue, an additional ssh daemon will be started at port '1022'. Do you want to continue? Continue [yN]Press Enter to acknowledge the auxiliary SSH daemon notice and proceed.
Starting additional sshd To make recovery in case of failure easier, an additional sshd will be started on port '1022'. If anything goes wrong with the running ssh you can still connect to the additional one. If you run a firewall, you may need to temporarily open this port. As this is potentially dangerous it's not done automatically. You can open the port with e.g.: 'iptables -I INPUT -p tcp --dport 1022 -j ACCEPT' To continue please press [ENTER]Enter
yand press Enter to begin downloading and installing the upgrade packages.Reading package lists... Done Building dependency tree... Done Reading state information... Done Do you want to start the upgrade? 7 packages are going to be removed. 164 new packages are going to be installed. 948 packages are going to be upgraded. You have to download a total of 1,712 M. This download will take about 5 minutes with a 40Mbit connection and about 45 minutes with a 5Mbit connection. Fetching and installing the upgrade can take several hours. Once the download has finished, the process cannot be canceled. Continue [yN] Details [d]Use the arrow keys to select the country of origin for your keyboard and press Enter when the
Configuring keyboard-configurationdialog appears.Use the arrow keys to select the specific keyboard layout variant for your country and press Enter to confirm.
Press Enter to select
Nand keep the existing/etc/systemd/journald.conffile when prompted.Configuration file '/etc/systemd/journald.conf' ==> Modified (by you or by a script) since installation. ==> Package distributor has shipped an updated version. What would you like to do about it ? Your options are: Y or I : install the package maintainer's version N or O : keep your currently-installed version D : show the differences between the versions Z : start a shell to examine the situation The default action is to keep your current version. *** journald.conf (Y/I/N/O/D/Z) [default=N] ?Select
keep the local version currently installedand press Enter when the upgrade tool prompts about/etc/ssh/sshd_config.Select
keep the local version currently installedand press Enter when prompted about/etc/default/grub.Press Enter to select
Nand keep the current/etc/cloud/cloud.cfgfile.Configuration file «/etc/cloud/cloud.cfg» ==> Modified (by you or by a script) since installation. ==> Package distributor has shipped an updated version. What would you like to do about it ? Your options are: Y or I : install the package maintainer's version N or O : keep your currently-installed version D : show the differences between the versions Z : start a shell to examine the situation The default action is to keep your current version. *** cloud.cfg (Y/I/N/O/D/Z) [default=N] ?Enter
dto review the list of obsolete packages, then enteryand press Enter to remove them.update-initramfs: Generating /boot/initrd.img-7.0.0-15-generic ... Reading package lists... Done Building dependency tree... Done Reading state information... Done Searching for obsolete software Reading state information... Done Remove obsolete packages? 109 packages are going to be removed. Removing the packages can take several hours. Continue [yN] Details [d]Wait for the upgrade to complete — the process typically takes 30 minutes or longer depending on the packages installed on the server. Enter
yand press Enter when prompted to restart.All snaps up to date. System upgrade is complete. Restart required To finish the upgrade, a restart is required. If you select 'y' the system will be restarted. Continue [yN]
Test the Upgraded Ubuntu 26.04 Server
After the server restarts, confirm that the upgrade succeeded and the system is running Ubuntu 26.04 LTS. Follow the steps below to verify the distribution version, kernel, and firewall configuration.
Display the active distribution information.
console$ cat /etc/os-release
Output:
PRETTY_NAME="Ubuntu 26.04 LTS" NAME="Ubuntu" VERSION_ID="26.04" VERSION="26.04 (Resolute Raccoon)" VERSION_CODENAME=resolute ID=ubuntu ID_LIKE=debian HOME_URL="https://www.ubuntu.com/" SUPPORT_URL="https://help.ubuntu.com/" BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/" PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy" UBUNTU_CODENAME=resolute LOGO=ubuntu-logoCheck the running kernel version.
console$ uname -mrs
Output:
Linux 7.0.0-15-generic x86_64Remove the temporary UFW rule for port
1022.console$ sudo ufw delete allow 1022/tcp
Fix Post-upgrade Repository Issues
Third-party APT repositories configured on the server may still reference the Ubuntu 24.04 (Noble Numbat) codename and fail to fetch updates until they are corrected. Follow the steps below to inspect repository sources and update all packages.
List the files in the APT sources directory.
console$ ls /etc/apt/sources.list.d
Output:
docker.list.disabled ubuntu.sources ubuntu.sources.curtin.origUpdate any repository files that still reference the Ubuntu 24.04 codename to use the Ubuntu 26.04 sources instead.
Refresh the package information index.
console$ sudo apt update
Output:
Hit:1 http://ubuntu.mirror.constant.com resolute InRelease Hit:2 http://ubuntu.mirror.constant.com resolute-updates InRelease Hit:3 http://ubuntu.mirror.constant.com resolute-backports InRelease Hit:4 http://security.ubuntu.com/ubuntu resolute-security InRelease All packages are up to date.Verify that all repository entries reference
resoluterather thannoble.Apply any available package upgrades.
console$ sudo apt upgrade
Output:
Summary: Upgrading: 0, Installing: 0, Removing: 0, Not Upgrading: 0Remove unused packages and clear the package cache.
console$ sudo apt autoremove -y && sudo apt autoclean
Output:
Summary: Upgrading: 0, Installing: 0, Removing: 0, Not Upgrading: 0 Del linux-headers-6.8.0-111 6.8.0-111.111 [13.7 MB] Del linux-modules-6.8.0-111-generic 6.8.0-111.111 [39.2 MB] Del linux-image-6.8.0-111-generic 6.8.0-111.111 [14.8 MB] Del linux-modules-extra-6.8.0-111-generic 6.8.0-111.111 [113 MB] ...
Conclusion
You have upgraded your server from Ubuntu 24.04 LTS to Ubuntu 26.04 LTS (Resolute Raccoon). The system now runs the Linux 7.0 kernel with updated packages, security patches, and the improvements introduced in this LTS release. For more information about new features and upgrade considerations, visit the official Ubuntu 26.04 release notes.