Ubuntu does not remove old kernel/initrd versions from boot out of box. This configuration causes your /boot to grow till there is no space left. Of course you can fix this by dropping to terminal: #sudo apt autoremove To fix that silently on every run of apt upgrade i changed /etc/apt/apt.conf.d/50unattended-upgrades: // Do automatic removal of new unused dependencies after the upgrade // (equivalent to apt-get autoremove) Unattended-Upgrade::Remove-Unused-Dependencies "true"; Source: https://help.ubuntu.com/community/AutomaticSecurityUpdates