一、更换yum源，使用国内163源
确保已安装 下载组件wget
yum -y install wget
先备份/etc/yum.repos.d/CentOS-Base.repo (改名)
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
切换到目录/etc/yum.repos.d下载repo文件, (http://mirrors.163.com/.help/centos.html)
wget http://mirrors.163.com/.help/CentOS6-Base-163.repo (在哪个目录执行wget 就下载在哪里 )
改名
mv /etc/yum.repos.d/CentOS6-Base-163.repo /etc/yum.repos.d/CentOS-Base.repo
生成缓存
yum clean all
yum makecache
参考官方说明：
http://mirrors.163.com/.help/centos.html
wget -O /etc/yum.repos.d/CentOS-Base.repo
http://mirrors.aliyun.com/repo/Centos-7.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-$releasever - Base - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
http://mirrors.aliyuncs.com/centos/$releasever/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
http://mirrors.aliyuncs.com/centos/$releasever/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
http://mirrors.aliyuncs.com/centos/$releasever/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
http://mirrors.aliyuncs.com/centos/$releasever/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/$releasever/contrib/$basearch/
http://mirrors.aliyuncs.com/centos/$releasever/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
/$releasever/换成/7/
# 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-$releasever - Base - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/7/os/$basearch/
http://mirrors.aliyuncs.com/centos/7/os/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/7/updates/$basearch/
http://mirrors.aliyuncs.com/centos/7/updates/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/7/extras/$basearch/
http://mirrors.aliyuncs.com/centos/7/extras/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/7/centosplus/$basearch/
http://mirrors.aliyuncs.com/centos/7/centosplus/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#contrib - packages by Centos Users
[contrib]
name=CentOS-$releasever - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos/7/contrib/$basearch/
http://mirrors.aliyuncs.com/centos/7/contrib/$basearch/
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
二、利用iso镜像制作本地yum源
1.创建iso存放目录和挂载目录
[root@desktop ~]# cd /mnt/ [root@desktop mnt]# mkdir iso cdrom
2.将iso镜像文件上传到/mnt/iso文件夹下
(如果是虚拟机的话可以使用scp命令)
3.将/mnt/iso下的iso文件挂载到/mnt/cdrom目录
[root@desktop ~]# mount -o loop /mnt/iso/rhel-server-7.0-x86_64-dvd.iso /mnt/cdrom/ mount: /dev/loop0 写保护，将以只读方式挂载.
(mount命令 -o指定选项，loop用来把一个文件当成硬盘分区mount到目录)
4.编辑/etc/yum.repos.d/myself.repo,如果/etc/yum.repos.d/路径下有其他*.repo文件的话，先备份删除，然后再编辑myself.repo文件
[root@desktop ~]# cd /etc/yum.repos.d/ [root@desktop yum.repos.d]# vim myself.repo
[base] name=RedHat baseurl=file:///mnt/cdrom enabled=1 gpgckeck=0 gpgkey=file:///mnt/cdrom/RPM-GPG-KEY-redhat-release
其中RPM-GPG-KEY-redhat-release可以在/mnt/cdrom/下找到复制粘贴到这里就可以了。
5.测试
清除yum缓存
[root@desktop yum.repos.d]# yum clean all
尝试安装httpd
[root@desktop yum.repos.d]# yum install httpd
由于上面使用的是手动挂载，所以每次重启之后都需要再次手动挂载，比较麻烦
编辑/etc/fstab文件添加内容实现自动挂载，具体做法是：
[root@desktop ~]# nano /etc/fstab
在最后一行添加：
/mnt/iso/rhel-server-7.0-x86_64-dvd.iso /mnt/cdrom iso9660 loop 0 0
保存退出即可。
然后重启检测就可以了。