Ubuntu升级系统版本

step 1：sudo apt update
step 2：apt-get upgrade && sudo apt dist-upgrade
step 3：sudo apt install update-manager-core
step 4：sudo vim /etc/update-manager/release-upgrades
更改最后一行
Prompt=normal
保存退出
step 5：do-release-upgrade
step 6 ：reboot

转：https://blog.youkuaiyun.com/isjbirug/article/details/78947894