yum源更换为本地光盘

下面来示范一下如何使用光盘文件配置yum库。注意：一定要把/etc/yum.repos.d里的其他文件移到其他地方，否则会报错

进入到/etc/yum.repos.d目录中后创建Yum配置文件：
[root@linuxprobe ~]# cd /etc/yum.repos.d/
[root@linuxprobe yum.repos.d]# vim rhel7.repo
[rhel7]
name=rhel7
baseurl=file:///media/cdrom
enabled=1
gpgcheck=0
[root@linuxprobe yum.repos.d]# mkdir -p /media/cdrom
[root@linuxprobe yum.repos.d]# mount /dev/cdrom /media/cdrom    //挂载
mount: /dev/sr0 is write-protected, mounting read-only
[root@linuxprobe yum.repos.d]# vim /etc/fstab   //开机自动挂载
/dev/cdrom /media/cdrom iso9660 defaults 0 0

配置好之后，可以使用yum list查看是否配置成功，如果配置成功会显示一堆可用的安装包。如果有报错的话，可以试着把除了这个配置文件外的其他配置文件全部删除（因为其他文件可能都是需要联网的，一旦连不了网，yum list 好像就会异常中断了）

下面这些是关于yum配置文件的介绍，有兴趣可以看一下
yum主配置文件

[root@bogon ~]# cat /etc/yum.conf
[main]  //所有仓库公共的配置
cachedir=/var/cache/yum/$basearch/$releasever //缓存目录
keepcache=0 //程序包在安装完成后不再保存至缓存中
debuglevel=2    // 程序安装时的输出信息，数字越大输出信息越多。生产环境中关闭最好，但是开启可以让我们快速定位安装中出现问题的所在
logfile=/var/log/yum.log    //日志路径
exactarch=1 //安装程序的版本和当前平台保持一致
obsoletes=1 //检查包已被废弃
gpgcheck=1  //检查源合法性和包的完整性
plugins=1   //支持插件
installonly_limit=5 //每次安装包的数量限制为5个
bugtracker_url=http://bugs.centos.org/set_project.php?project_id=23&ref=http://bugs.centos.org/bug_report_page.php?category=yum //bug追踪的路径
distroverpkg=centos-release //判断当前系统信息
#  This is the default, if you make this bigger yum won't see if the metadata
# is newer on the remote and so you'll "gain" the bandwidth of not having to
# download the new metadata and "pay" for it by yum not having correct
# information.
#  It is esp. important, to have correct metadata, for distributions like
# Fedora which don't keep old packages around. If you don't like this checking
# interupting your command line usage, it's much better to have something
# manually check the metadata once an hour (yum-updatesd will do this).
# metadata_expire=90m
# PUT YOUR REPOS HERE OR IN separate files named file.repo
# in /etc/yum.repos.d
[root@bogon ~]#

各配置文件

[root@bogon ~]# ls /etc/yum.repos.d/
CentOS-Base.repo  CentOS-Debuginfo.repo  CentOS-Media.repo    CentOS-Vault.repo
CentOS-CR.repo    CentOS-fasttrack.repo  CentOS-Sources.repo
[root@bogon ~]# cat /etc/yum.repos.d/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-$releasever - Media
baseurl=file:///media/CentOS/
        file:///media/cdrom/
        file:///media/cdrecorder/
gpgcheck=1
enabled=0   //此仓库不被使用
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
[root@bogon ~]#
[root@bogon ~]# cat /etc/yum.repos.d/CentOS-Base.repo
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client.  You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
#
[base]
name=CentOS-$releasever - Base
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus&infra=$infra
#baseurl=http://mirror.centos.org/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
[root@bogon ~]# 

yum -y install httpd 自动确认安装httpd
yum list //列出全部程序包