Ubuntu 14.04.5 LTS 升級到 Ubuntu 16.04.3 LTS
1. apt-get update
2. apt-get upgrade

3. 升級當前系統版本:apt-get dist-upgrade

4. 開始升級新系統版本:do-release-upgrade

4.1. 點擊『Enter』

4.2. Do you want to start the upgrade?

4.3. Configuring sysstat

4.4. Configuring libssl1.0.0:amd64

4.5. Configuration file '/etc/bash.bashrc'

4.6. Configuration file '/etc/ntp.conf'

4.7. Configuration file '/etc/rsyslog.conf'

4.8. Configuration file '/etc/snmp/snmpd.conf'

4.9. Configuring unattended-upgrades

4.10. Remove obsolete packages

4.11. System upgrade is complete

5. lsb_release -a

6. 操作影片
7. 參考資料
https://yungke.me/ubuntu-14-04-upgrade-ubuntu-16-04-lts/
https://www.howtoing.com/upgrade-ubuntu-14-04-lts-to-ubuntu-16-04-lts