centos7出现yum之类的问题的时候可能是加入的一些源导致的问题最佳的解决方案

//傻逼的我胡搞出现不知道添加什么软件源到/etc/yum.repo中结果出现了一堆错-搜了很长时间没解决-算了-返璞归真（回到初始的状态）吧，看了一下别人的阿里云的服务器中初始的时候都有什么源 结果就（CentOS-Base.repo ,epel.repo）就这两个源 好吧现在把所有的除了这两个源都编程 **.repo.bak
然后 yum clean all yum makecache
这样就可以了

[root@iz2ze1ci0m3dzopy4m0byfz ~]# yum update
Loaded plugins: fastestmirror
base | 3.6 kB 00:00:00
epel | 3.2 kB 00:00:00
extras | 3.4 kB 00:00:00
mysql-connectors-community | 2.5 kB 00:00:00
mysql-tools-community | 2.5 kB 00:00:00
mysql57-community | 2.5 kB 00:00:00
Could not retrieve mirrorlist http://apt.sw.be/redhat/el6/en/mirrors-rpmforge error was
14: curl#6 – “Could not resolve host: apt.sw.be; Name or service not known”
http://apt.sw.be/redhat/el6/en/x86_64/rpmforge/repodata/repomd.xml: [Errno 14] curl#6 – “Could not resolve host: apt.sw.be; Name or service not known”
Trying other mirror.

One of the configured repositories failed (RHEL 7 – RPMforge.net – dag),
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. Run the command with the repository temporarily disabled          yum --disablerepo=rpmforge ...     4. Disable the repository permanently, 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 rpmforge      or          subscription-manager repos --disable=rpmforge     5. 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=rpmforge.skip_if_unavailable=true  

failure: repodata/repomd.xml from rpmforge: [Errno 256] No more mirrors to try.
http://apt.sw.be/redhat/el6/en/x86_64/rpmforge/repodata/repomd.xml: [Errno 14] curl#6 – “Could not resolve host: apt.sw.be; Name or service not known”
但是这个错我真的不知道是什么意思-哪位大佬遇到这个错知道是什么意思能解决的话，麻烦留言。