装YUM过程
#rpm -qa | grep yum //查看已安装的yum
#rpm -qa | grep yum | xargs rpm -e --nodeps
//卸载已安装的yum
#wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-3.2.29-81.el6.centos.noarch.rpm
#wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
#wget http://mirrors.163.com/centos/6/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.30-41.el6.noarch.rpm
#wget http://mirrors.163.com/centos/6/os/x86_64/Packages/python-urlgrabber-3.9.1-11.el6.noarch.rpm
#wget http://mirrors.163.com/centos/6/os/x86_64/Packages/python-iniparse-0.3.1-2.1.el6.noarch.rpm
#ls
python-iniparse-0.3.1-2.1.el6.noarch.rpm
python-urlgrabber-3.9.1-11.el6.noarch.rpm
yum-3.2.29-81.el6.centos.noarch.rpm
yum-metadata-parser-1.1.2-16.el6.x86_64.rpm
yum-plugin-fastestmirror-1.1.30-41.el6.noa