Ubuntu更换国内源

1、备份软件源

cd /etc/apt/
ls
sudo cp ./sources.list ./sources.list.curtin.old

2、修改软件源

sudo vim sources.list
    :%s/archive.ubuntu/mirrors.aliyun/g
    :%s/security.ubuntu/mirrors.aliyun/g
    :wq

3、更新已安装软件、软件源

sudo apt upgrade
sudo apt update