Linux拥有众多的发行版，每个发行版都有提供镜像，但是，有些镜像的下载速度参差不齐，偶尔会有更新失败的情况。

下面以修改 Ubuntu 软件源为中科大为例进行说明。

镜像地址：https://mirrors.ustc.edu.cn/

1、备份原配置文件

1.  # cp /etc/apt/sources.list /etc/apt/sources.list.backup

2、更改配置文件

编辑/etc/apt/sources.list文件, 将内容修改为：

Xenial(16.04)

1.  deb https://mirrors.ustc.edu.cn/ubuntu/ xenial main restricted

2.  deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-updates main restricted

3.  deb https://mirrors.ustc.edu.cn/ubuntu/ xenial universe

4.  deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-updates universe

5.  deb https://mirrors.ustc.edu.cn/ubuntu/ xenial multiverse

6.  deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-updates multiverse

7.  deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-backports main restricted universe multiverse

8.  deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-security main restricted

9.  deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-security universe

10.deb https://mirrors.ustc.edu.cn/ubuntu/ xenial-security multiverse

Trusty(14.04)

1.  deb https://mirrors.ustc.edu.cn/ubuntu/ trusty main restricted

2.  deb https://mirrors.ustc.edu.cn/ubuntu/ trusty-updates main restricted

3.  deb https://mirrors.ustc.edu.cn/ubuntu/ trusty universe

4.  deb https://mirrors.ustc.edu.cn/ubuntu/ trusty-updates universe

5.  deb https://mirrors.ustc.edu.cn/ubuntu/ trusty multiverse

6.  deb https://mirrors.ustc.edu.cn/ubuntu/ trusty-updates multiverse

7.  deb https://mirrors.ustc.edu.cn/ubuntu/ trusty-backports main restricted universe multiverse

8.  deb https://mirrors.ustc.edu.cn/ubuntu/ trusty-security main restricted

9.  deb https://mirrors.ustc.edu.cn/ubuntu/ trusty-security universe

10.deb https://mirrors.ustc.edu.cn/ubuntu/ trusty-security multiverse

Precise(12.04)

1.  deb https://mirrors.ustc.edu.cn/ubuntu/ precise main restricted

2.  deb https://mirrors.ustc.edu.cn/ubuntu/ precise-updates main restricted

3.  deb https://mirrors.ustc.edu.cn/ubuntu/ precise universe

4.  deb https://mirrors.ustc.edu.cn/ubuntu/ precise-updates universe

5.  deb https://mirrors.ustc.edu.cn/ubuntu/ precise multiverse

6.  deb https://mirrors.ustc.edu.cn/ubuntu/ precise-updates multiverse

7.  deb https://mirrors.ustc.edu.cn/ubuntu/ precise-backports main restricted universe multiverse

8.  deb https://mirrors.ustc.edu.cn/ubuntu/ precise-security main restricted

9.  deb https://mirrors.ustc.edu.cn/ubuntu/ precise-security universe

10.deb https://mirrors.ustc.edu.cn/ubuntu/ precise-security multiverse

3、更新

1.  # apt-get update