如何修改CentOS的yum源

1. 修改CentOS的yum源[可选]
shell# cd /etc/yum.repos.d
shell# mv CentOS-Base.repo CentOS-Base.repo.save
shell# wget http://centos.ustc.edu.cn/CentOS-Base.repo.5
shell# mv CentOS-Base.repo.5 CentOS-Base.repo
2. 更新系统
shell# yum update -y
shell# reboot