Ubuntu 24.04 LTS remains fully supported, but Ubuntu 26.04 LTS ships the Linux 7.0 kernel and updated security defaults. This guide upgrades a live Ubuntu 24.04 server to Ubuntu 26.04 LTS in-place using do-release-upgrade , handling the auxiliary SSH daemon, configuration file conflicts, and obsolete package removal. By the end, you'll have a running Ubuntu 26.04 system with the kernel version confirmed. Prepare for the Upgrade 1. Update the APT package index and upgrade all installed packages: $ sudo apt update $ sudo apt upgrade -y Enter fullscreen mode Exit fullscreen mode 2. Remove obsolete packages: $ sudo apt autoremove -y Enter fullscreen mode Exit fullscreen mode 3. Install the upgrade manager: $ sudo apt install update-manager-core -y Enter fullscreen mode Exit fullscreen mode Open the Auxiliary SSH Port The do-release-upgrade tool starts an auxiliary SSH daemon on port 1022. Opening this port prevents being locked out if the primary SSH connection drops during the upgrade.…