sudo cp /etc/apt/sources.list /etc/apt/sources_origin.list # 备份 sudo gedit /etc/apt/sources.list # 删除原来的内容
deb http://mirrors.aliyun.com/ubuntu/ xenial main deb-src http://mirrors.aliyun.com/ubuntu/ xenial main deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main deb http://mirrors.aliyun.com/ubuntu/ xenial universe deb-src http://mirrors.aliyun.com/ubuntu/ xenial universe deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates universe deb http://mirrors.aliyun.com/ubuntu/ xenial-security main deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main deb http://mirrors.aliyun.com/ubuntu/ xenial-security universe deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security universe
sudo apt-get update
sudo cp /etc/apt/sources.list /etc/apt/sources_origin.list # 备份 sudo gedit /etc/apt/sources.list # 删除原来的内容
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
sudo apt-get update
# 1. 备份原镜像文件，便于后期恢复 $ sudo mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup # 2.下载新的CentOS-Base.repo 到/etc/yum.repos.d/ $ sudo wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo # 3. 清除缓存 $ sudo yum clean all # 4. 生成缓存 $ sudo yum makecache
https://blog.csdn.net/liangontheway/article/details/103509635
原文：https://www.cnblogs.com/gzming/p/14258797.html