centos6 yum 源失效 404

今天下午想装点东西。。 突然发现所有的6 yum源都失效了 

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

http://mirrors.aliyun.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.

不管是阿里 163 清华 都只剩一个readme  去官方一看  官方都没了， 一顿好找 终于找到一个

[base]
name=CentOS-$releasever
failovermethod=priority
baseurl=https://vault.centos.org/6.9/os/x86_64/
gpgcheck=0

把repo文件里的东西都删掉  换上这个就行了