Centos7系统安装yum遇到的问题failure: repodata/repomd.xml from base: [Errno 256] No more mirrors to try. http:

当遇到这个问题的时候，发现网上也有很多人也在问同样的问题。但是发现大家问的问题，很少有人能解释得很清楚，而且很多人的解决方法复杂且不能解决问题。我查了近二十篇博客和文章，对照做了，但是基本解决不了问题。

http://mirrors.ustc.edu.cn/help/centos.html

http://mirrors.163.com/.help/centos.html

https://blog.youkuaiyun.com/dreamchasering/article/details/77160477

https://blog.youkuaiyun.com/shaoqiufeng/article/details/78785806

https://blog.youkuaiyun.com/orangleliu/article/details/40588799

https://www.cnblogs.com/yizhichun/p/6339742.html

https://blog.youkuaiyun.com/james_jr10/article/details/78357600（这个好像很厉害，但是写得不清晰，误我前程啊）

https://segmentfault.com/q/1010000000716991/a-1020000000717340

你来看看，这些问题有多少人问？但是能解决实际问题的却很少！！！

 

下面由我给出一种最简单最有效的方法。耐心看下去哦！

问题所在：

[root@cit-server6-s1-372 yum.repos.d]# yum makecache
Loaded plugins: fastestmirror
base                                                                     | 5.6 kB  00:00:00     
http://mirrors.163.com/centos/7/os/x86_64/repodata/repomd.xml: [Errno -1] Error importing repomd.xml for base: Damaged repomd.xml file
Trying other mirror.


 One of the configured repositories failed (CentOS-7 - Base - 163.com),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Disable the repository, so yum won't use it by default. Yum will then
        just ignore the repository until you permanently enable it again or use
        --enablerepo