Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stoc

今天在使用yum安装文件时，出现了以下问题：

root@localhost opt]# yum updateLoaded plugins: fastestmirrorCould not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was12: Timeout on http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock: (28, 'Resolving timed out after 30568 milliseconds') One of the configured repositories failed (Unknown), 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=<repoid> ...     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 <repoid>        or            subscription-manager repos --disable=<repoid>     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=<repoid>.skip_if_unavailable=trueCannot find a valid baseurl for repo: base/7/x86_64

解决方案：
编辑/etc/resolv.conf这个文件，在文件末尾添加nameserver 114.114.114.114这即可
命令：

vim /etc/resolv.conf

修改后的文件如下图：

参考链接：http://www.landui.com/help/show-2739.html