Linux（Centos7）更换为阿里yum源

一、为什么把 CentOS 7 默认 yum 源换成阿里云镜像

CentOS 7 官方源在部分网络环境下访问较慢，加上官方停止维护后很多镜像同步不稳定。把 /etc/yum.repos.d/CentOS-Base.repo 替换为阿里云镜像，可以显著提升 yum install 的下载速度与稳定性，是服务器初始化时最常见的第一步。

二、备份原有 repo 文件

任何改源操作前先备份，出问题可一键还原：

cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak

三、一键替换为阿里云 yum 源

直接下载阿里云提供的 CentOS-7 repo 文件覆盖即可：

wget -O /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo

如果服务器没有 wget，可改用 curl -o，或按下一节手动写入。

四、手动写入 repo 内容（无外网下载时）

在无法外网下载的场景，可手动创建 /etc/yum.repos.d/CentOS-Base.repo，核心配置如下：

[base]
name=CentOS-$releasever - Base - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
        http://mirrors.aliyuncs.com/centos/$releasever/os/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

[updates]
name=CentOS-$releasever - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
        http://mirrors.aliyuncs.com/centos/$releasever/updates/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

[extras]
name=CentOS-$releasever - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
        http://mirrors.aliyuncs.com/centos/$releasever/extras/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

[centosplus]
name=CentOS-$releasever - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
        http://mirrors.aliyuncs.com/centos/$releasever/centosplus/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

[contrib]
name=CentOS-$releasever - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/contrib/$basearch/
        http://mirrors.aliyuncs.com/centos/$releasever/contrib/$basearch/
        http://mirrors.cloud.aliyuncs.com/centos/$releasever/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7

五、生成缓存并验证

yum clean all
yum makecache

无报错即代表新源生效。

六、顺手安装常用基础工具

换源后建议一次性装上编译与排障常用的工具链：

yum install -y gcc gcc-c++ make cmake wget lrzsz perl crontabs patch net-tools unzip zlib zlib-devel pcre pcre-devel libxml2 libxml2-devel bzip2-devel libcurl-devel ncurses ncurses-devel openssl openssl-devel telnet

qidao123.com企服评测-应用市场 编辑提示：修改 yum 源属于服务器基础配置，建议在测试机先验证再批量推送到生产；阿里云镜像地址以官方 mirrors.aliyun.com 公布为准。