When the redhat system is installed online, the system prompts This system is not registered with RHN. 1. Uninstall the redhat yum component www.2cto.com [root @ localhost ~]. # Rpm-qa | grep yum | xargs rpm-e -- nodeps 2. Download The centos yum component [root @ localhost ~] # Wget requests ~] # Wget requests ~] # Wget http://centos.ustc.edu.cn/centos/5/ OS /i386/CentOS/yum-3.2.22-37.el5.centos.noarch.rpm 3. Install centos yum components [root @ localhost ~] # Rpm-ivh *. rpm 4. Back up the/etc/yum. repos. d/Redhat source [root @ localhost ~] # Mv rhel-debuginfo.repo rhel-debuginfo.repo.bak [root @ localhost ~] # Mv rhel-source.repo rhel-source.repo.bak 5, download update source, coexist in the system directory [root @ localhost ~] # Wget http://docs.linuxtone.org/soft/lemp/centos-base.repoin directory/etc/yum. repos. d/6. Generate cache and install [root @ localhost ~] # Yum makecache