Ubuntu、CentOs更换源（阿里云的源）

ubuntu

1. 备份当前的apt配置文件

   sudo mv /etc/apt/sources.list /etc/apt/sources.list.backup

2. 编辑配置文件，将以下内容写到文件中sudo vi /etc/apt/sources.list

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

3. 更新

   更新源

   sudo apt update

   更新系统中已安装的软件包

   sudo apt upgrade

centos

1. 备份当前的yum源

   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/

   wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
   或者
   curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

3. 清空并生成缓存

   yum clean all
   yum makecache