1.Redhat reason why this error occurs because there is no registered RHN, we only need to look at the source yum update on it. Use the command cd /etc/yum.repos.d/ into the configuration directory of yum.
2. Enter wget http://docs.linuxtone.org/soft/lemp/CentOS-Base.repo command in a terminal, download CentOS- Base.repo file.
Music Videos rhel-debuginfo.repo RHEL 3.-debuginfo.repo_bak
4. Then the original backup rhel-debuginfo.repo look, using the command mv CentOS-Base.repo rhel-debuginfo.repo, to rename the CentOS- Base.repo rhel-debuginfo.repo.
Reproduced in: https: //my.oschina.net/garyun/blog/602894