1、分配光驱
选择本地的iso系统镜像文件，或者在光驱中放入系统安装盘。之后，在桌面可以看到RHEL-7.2-Server的光盘图标。
2、查看光驱挂载的位置
使用df -h 命令可以看到光驱或镜像文件挂载的位置。
3、修改本地yum源的配置文件
[root@rhel7 ~]# mv /etc/yum.repos.d/redhat.repo /etc/yum.repos.d/redhat.repo_bak ---备份原来的配置文件
[root@rhel7 ~]# cat /etc/yum.repos.d/cdrom.repo ---使用vi命令新建cdrom.repo，添加内容如下
[cdrom]
name = cdrom
baseurl = file:///run/media/root/RHEL-7.2\ Server.x86_64/ ----注意该路径不能直接用上图中显示的挂载路径，因为中间有空格，要添加反斜杠转义。
gpgcheck =
enable =
[root@rhel7 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/rhel-root .5G .1G .5G % /
devtmpfs 986M 986M % /dev
tmpfs 1001M 192K 1001M % /dev/shm
tmpfs 1001M 8.8M 992M % /run
tmpfs 1001M 1001M % /sys/fs/cgroup
/dev/sda1 497M 140M 358M % /boot
tmpfs 201M .0K 201M % /run/user/
tmpfs 201M 20K 201M % /run/user/
/dev/sr0 .8G .8G % /run/media/root/RHEL-7.2 Server.x86_64
[root@rhel7 ~]# cd /run/media/root/RHEL-7.2 Server.x86_64
bash: cd: /run/media/root/RHEL-7.2: No such file or directory
[root@rhel7 ~]# cd /run/media/root/RHEL-7.2\ Server.x86_64/
[root@rhel7 RHEL-7.2 Server.x86_64]# ls
addons GPL LiveOS release-notes RPM-GPG-KEY-redhat-release
EFI images media.repo repodata TRANS.TBL
EULA isolinux Packages RPM-GPG-KEY-redhat-beta
[root@rhel7 RHEL-7.2 Server.x86_64]#
4、测试Yum源是否可用
[root@rhel7 RHEL-7.2 Server.x86_64]# yum install httpd
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Resolving Dependencies
--> Running transaction check
---> Package httpd.x86_64 :2.4.-.el7 will be installed
--> Processing Dependency: httpd-tools = 2.4.-.el7 for package: httpd-2.4.-.el7.x86_64
--> Processing Dependency: /etc/mime.types for package: httpd-2.4.-.el7.x86_64
--> Processing Dependency: libapr-.so.()(64bit) for package: httpd-2.4.-.el7.x86_64
--> Processing Dependency: libaprutil-.so.()(64bit) for package: httpd-2.4.-.el7.x86_64
--> Running transaction check
---> Package apr.x86_64 :1.4.-.el7 will be installed
---> Package apr-util.x86_64 :1.5.-.el7 will be installed
---> Package httpd-tools.x86_64 :2.4.-.el7 will be installed
---> Package mailcap.noarch :2.1.-.el7 will be installed
--> Finished Dependency Resolution Dependencies Resolved ================================================================================================================================
Package Arch Version Repository Size
================================================================================================================================
Installing:
httpd x86_64 2.4.-.el7 cdrom 1.2 M
Installing for dependencies:
apr x86_64 1.4.-.el7 cdrom k
apr-util x86_64 1.5.-.el7 cdrom k
httpd-tools x86_64 2.4.-.el7 cdrom k
mailcap noarch 2.1.-.el7 cdrom k Transaction Summary
================================================================================================================================
Install Package (+ Dependent packages) Total download size: 1.5 M
Installed size: 4.3 M
Is this ok [y/d/N]:
……
但是使用这种方式配置的本地YUM源的缺点是你得把ISO系统镜像一直挂载到系统里，如果你本地删除了镜像文件，则yum命令就不可用了。还有个问题就是，下次重启系统时，会自动从光驱启动到系统安装界面。
优点是配置简单、快速，想用的时候直接分配光驱，不想用时就移除，这样也不会占用存储空间。或者如果你的磁盘空间比较大，你也可以把整个光盘中的文件拷贝到系统中的某个目录下，如果修改cdrom.repo配置文件的中baseurl参数到对应目录即可。