由 dawei CentOS 开发者邮件列表显示，CentOS 6 已于11月30日 EOL，如果由于某种原因，您被困在 CentOS 操作系统的现在EOL(生命的尽头)版本，您将无法再yum upgrade成功运行。yum upgrade在 CentOS 6 中运行将产生以下结果：
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 retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again
CentOS 6 停产后如何修复 yum?
更换yum源
CentOS官方：http://vault.centos.org/
阿里云镜像：
http://mirrors.aliyun.com/centos-vault/
CentOS 6 停产后如何修复 yum?
1、关闭fastestmirror
[root@localhost ~]# vi /etc/yum/pluginconf.d/fastestmirror.conf
[main]
enabled=0 #修改为0
verbose=0
2、替换为官方Vault源
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak
#替换为官方Vault源
wget -O /etc/yum.repos.d/CentOS-Base.repo https://static.lty.fun/%E5%85%B6%E4%BB%96%E8%B5%84%E6%BA%90/SourcesList/Centos-6-Vault-Official.repo
3、替换为阿里云Vault镜像
wget -O /etc/yum.repos.d/CentOS-Base.repo https://static.lty.fun/%E5%85%B6%E4%BB%96%E8%B5%84%E6%BA%90/SourcesList/Centos-6-Vault-Aliyun.repo
修复 EPEL 存储库
curl https://www.getpagespeed.com/files/centos6-epel-eol.repo –output /etc/yum.repos.d/epel.repo
修复 SCLO 存储库
包含较新编译软件的存储库gcc可通过 Software Collections 获得。
但是，它的存储库同样消失了。改用 Vault 存储库：
yum -y install centos-release-scl
curl https://www.getpagespeed.com/files/centos6-scl-eol.repo –output /etc/yum.repos.d/CentOS-SCLo-scl.repo
curl https://www.getpagespeed.com/files/centos6-scl-rh-eol.repo –output /etc/yum.repos.d/Cen