[root@localhost ~]# mount /dev/cdrom /media/cdrom/mount: /dev/sr0 写保护，将以只读方式挂载

[root@localhost /]# cd /etc/yum.repos.d/[root@localhost yum.repos.d]# mkdir bak　　　　#创建一个文件夹来存放多余的配置文件[root@localhost yum.repos.d]# mv *.* bak/　　　　　　[root@localhost yum.repos.d]# cd bak/[root@localhost bak]# lsCentOS-Base.repo  CentOS-Debuginfo.repo  CentOS-Media.repo    CentOS-Vault.repoCentOS-CR.repo    CentOS-fasttrack.repo  CentOS-Sources.repo[root@localhost bak]# mv CentOS-Media.repo ../[root@localhost bak]# cd ../[root@localhost yum.repos.d]# vi CentOS-Media.repo 

# CentOS-Media.repo##  This repo can be used with mounted DVD media, verify the mount point for#  CentOS-7.  You can use this repo and yum to install items directly off the#  DVD ISO that we release.## To use this repo, put in your DVD and use it with the other repos too:#  yum --enablerepo=c7-media [command]## or for ONLY the media repo, do this:##  yum --disablerepo=\* --enablerepo=c7-media [command][c7-media]name=CentOS-$releasever - Mediabaseurl=file:///media/CentOS/        file:///media/cdrom/　　#本地yum源所在路径        file:///media/cdrecorder/gpgcheck=0   #这里为0不进行检查enabled=1　　　#这里为1　　启动gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7~                                                                  

[root@localhost /]# yum list  　　#后面东西太多了。。。