dnf包管理器克服了yum包管理器的一些瓶颈，提升了包括用户体验，内存占用，依赖分析，运行速度等。
CentOS 7 使用 dnf ，下载并安装下面包：
wget http://springdale.math.ias.edu/data/puias/unsupported/7/x86_64/dnf-conf0.6.4-2.sdl7.noarch.rpm
wget http://springdale.math.ias.edu/data/puias/unsupported/7/x86_64/dnf-0.6.42.sdl7.noarch.rpm
wget http://springdale.math.ias.edu/data/puias/unsupported/7/x86_64/python-dnf0.6.4-2.sdl7.noarch.rpm
wget https://mirrors.aliyun.com/centos/7/extras/x86_64/Packages/python2libcomps-0.1.8-12.el7.x86_64.rpm
wget https://mirrors.aliyun.com/centos/7/extras/x86_64/Packages/libcomps-0.1.812.el7.x86_64.rpm