修改阿里源为Ubuntu 18.04默认的源

备份/etc/apt/sources.list

cp /etc/apt/sources.list /etc/apt/sources.list.bak

在/etc/apt/sources.list文件前面添加如下条目
阿里源

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

更新

sudo apt-get update
sudo apt-get upgrade

另外其他几个国内源如下：

• 中科大源
  deb https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
  deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
  deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
  deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
  deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
  deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
  deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
  deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
  deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
  deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse

• 163源
  deb http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse
  deb http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse
  deb http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse
  deb http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse
  deb http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse
  deb-src http://mirrors.163.com/ubuntu/ bionic main restricted universe multiverse
  deb-src http://mirrors.163.com/ubuntu/ bionic-security main restricted universe multiverse
  deb-src http://mirrors.163.com/ubuntu/ bionic-updates main restricted universe multiverse
  deb-src http://mirrors.163.com/ubuntu/ bionic-proposed main restricted universe multiverse
  deb-src http://mirrors.163.com/ubuntu/ bionic-backports main restricted universe multiverse

• 清华源
  deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
  deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic main restricted universe multiverse
  deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
  deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
  deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
  deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
  deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
  deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
  deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
  deb-src https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse

Ubuntu 18.04修改默认源为国内源

原文：https://www.cnblogs.com/bluekang/p/13042096.html