How to upgrade from Ubuntu Linux 16.04 to 18.04

Type the apt command or apt-get command to upgrade existing system:

  sudo apt update

  sudo apt upgrade

Reboot the Linux box if kernel was updated

  sudo reboot

If you have a ufw firewall running on ufw, open ssh port 1022 using the following ufw syntax:

  sudo ufw allow 1022/tcp comment 'Temp open port ssh tcp port 1022 for upgrade'

Upgrade the operating system to the latest release from the command-line by typing the following command:

  sudo do-release-upgrade

After some time you will see “System upgrade is complete” message. Press y to restart your system to load updates kernel and operating system for your cloud server:

Verification

Login using the ssh command:

  ssh user@your-ubuntu-server

Verify Ubuntu Linux kernel version with uname:

  uname -r

Make sure all needed ports are open and running with the ss command or netstat command:

  sudo ss -tulpn

  sudo netstat -tulpn

Use grep command/egrep command or tail command/cat command to verify log files for errors:

  dmesg

  tail -f /path/to/log/files

  egrep -i 'err|cri' /var/log/nginx/error.log