1.百度中提供的安装办法
yum install epel-release -yyum install dnf
2. No package dnf available解决办法
运行一下几个命令：
wget http://springdale.math.ias.edu/data/puias/unsupported/7/x86_64/dnf-conf-0.6.4-2.sdl7.noarch.rpmwget http://springdale.math.ias.edu/data/puias/unsupported/7/x86_64//dnf-0.6.4-2.sdl7.noarch.rpmwget http://springdale.math.ias.edu/data/puias/unsupported/7/x86_64/python-dnf-0.6.4-2.sdl7.noarch.rpmyum install python-dnf-0.6.4-2.sdl7.noarch.rpm dnf-0.6.4-2.sdl7.noarch.rpm dnf-conf-0.6.4-2.sdl7.noarch.rpm
安装之后执行以下命令：
dnf --version
输出：
0.6.4 Repository epel is listed more than once in the configurationInstalled: dnf-0:0.6.4-2.sdl7.noarch at -03-09 11:31 Built : at -10-09 17:18 Installed: rpm-0:4.11.3-25.el7.x86_64 at -01-09 10:21 Built : CentOS BuildSystem <> at -08-03 03:48
安装成功。
