相信已经有很多朋友在连接到 CentOS 6 的服务器后执行 yum 后发现报错。这是因为 CentOS 6 已经随着 2020 年 11 月的结束进入了 EOL（End of Life）。不过，CentOS 官方为不想抛弃 CentOS 6 的用户保留了最后一个版本的镜像，但这个镜像不会再有更新。
一键修复#
sed -i "s|enabled=1|enabled=0|g" /etc/yum/pluginconf.d/fastestmirror.conf
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
curl -o /etc/yum.repos.d/CentOS-Base.repo https://www.xmpan.com/Centos-6-Vault-Aliyun.repo
yum clean all
yum makecache
手动修复教程#
禁用 fastestmirror 插件#
vi /etc/yum/pluginconf.d/fastestmirror.conf
# 修改以下行
enable=0
# 或者执行以下命令
sed -i "s|enabled=1|enabled=0|g" /etc/yum/pluginconf.d/fastestmirror.conf
替换 yum 源#
将之前的 yum 源备份：
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
然后选择以下任一方法来替换为新的 yum 源：
官方 Vault 源（海外服务器使用）#
curl -o /etc/yum.repos.d/CentOS-Base.repo https://www.xmpan.com/Centos-6-Vault-Official.repo
阿里云 Vault 镜像（国内服务器使用）#
curl -o /etc/yum.repos.d/CentOS-Base.repo https://www.xmpan.com/Centos-6-Vault-Aliyun.repo
错误详情#
以下是可能遇到的一些错误信息：
[root@c8-20 ~]# yum makecache
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
Eg. Invalid release/repo/arch combination/
removing mirrorlist with no valid mirrors: /var/cache/yum/x86_64/6/base/mirrorlist.txt
Error: Cannot find a valid baseurl for repo: base
或者
[root@li496-237 ~]# yum -y install unzip zip
Loaded plugins: fastestmirror
Setting up Install Process
Determining fastest mirrors
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
Eg. Invalid release/repo/arch combination/
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
Eg. Invalid release/repo/arch combination/
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
Eg. Invalid release/repo/arch combination/
http://mirrors.linode.com/centos/6/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"
Trying other mirror.
To address this issue please refer to the below knowledge base article
https://access.redhat.com/articles/1320623
If above article doesn't help to resolve this issue please open a ticket with Red Hat Support.
Error: Cannot retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again