Ubuntu 20.04 LTS 更换阿里云源

  1. 先备份原始源文件：
    sudo cp /etc/apt/source.list /etc/apt/source.list.backup

  2. 修改文件:
    vim /etc/apt/source.list

  3. 清除原有的内容，替换为aliyun源:

    deb http://mirrors.aliyun.com/ubuntu/ focal main restricted
    deb http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted
    deb http://mirrors.aliyun.com/ubuntu/ focal universe
    deb http://mirrors.aliyun.com/ubuntu/ focal-updates universe
    deb http://mirrors.aliyun.com/ubuntu/ focal multiverse
    deb http://mirrors.aliyun.com/ubuntu/ focal-updates multiverse
    deb http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
    deb http://mirrors.aliyun.com/ubuntu/ focal-security main restricted
    deb http://mirrors.aliyun.com/ubuntu/ focal-security universe
    deb http://mirrors.aliyun.com/ubuntu/ focal-security multiverse

  4. 保存，并执行更新：

    sudo  apt update
    sudo  apt upgrade