【操作系统】RedHat 7.2 yum源报错

RedHat 7.2 的yum源替换成CentOS 7.2 的yum源之后运行如下命令时报错

# yum install rp-pppoe -y
Loaded plugins: fastestmirror, product-id, search-disabled-repos, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
base                                                                                                          | 8.4 kB  00:00:00     
http://mirrors.163.com/centos/7.2.1511/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-$releasever-Base),
 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 for temporary usage:

            yum-config-manager --disable base

     4. Configure the failing repository to be skipped, if it is unavailable.
        Note that yum will try to contact the repo. when it runs most commands,
        so will have to try and fail each time (and thus. yum will be be much
        slower). If it is a very temporary problem though, this is often a nice
        compromise:

            yum-config-manager --save --setopt=base.skip_if_unavailable=true

failure: repodata/repomd.xml from base: [Errno 256] No more mirrors to try.
http://mirrors.163.com/centos/7.2.1511/os/x86_64/repodata/repomd.xml: [Errno -1] Error importing repomd.xml for base: Damaged repomd.xml file

经过翻阅网上大量的前人经验得知，有可能是以下两种情况导致以上错误

1.使用yum时没有连接到外网

2.错误中提到的repomd.xml文件被公司给墙了