This error occurs because the
1, network problems,
check your network conditions, can ping about Baidu, see if you can ping each other.
2, mirroring connection error
to use some search yum rpm package, the package can not be found because CentOS RedHat Enterprise Edition is compiled over, get rid of all the stuff about copyright issues. You can solve this problem after installing EPEL. EPEL (Extra Packages for Enterprise Linux) Enterprise Linux that is an extension package that provides a lot of components can be co-used Centos, after you install this basic common rpm can be found.
Solution
If this is the case, set your network connection.
For the second case, we just want Enterprise Linux repository configuration packages install the expansion pack. Specific methods are as follows
yum install epel-release
software can be installed before epel after re-installation failure.
Excerpt: https://www.jianshu.com/p/45919a9dbd5b](https://www.jianshu.com/p/45919a9dbd5b)
Reproduced in: https: //www.jianshu.com/p/106dfcd552c6