centos下修改yun源

废话不多说，下面记录了centos下更换系统默认yum源为网易yum源的操作过程：
1）备份原有的默认yum源
[root@bastion-IDC ~]# cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.bak

2）修改CentOS-Base.repo文件。将文件中的baseurl地址修改为网易163的yum源地址即可！
[root@bastion-IDC ~]# vim /etc/yum.repos.d/CentOS-Base.repo

1 2 3 4 5 6 7 8 9 扫描二维码关注公众号，回复： 6010832 查看本文章 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

# 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=$basearch&repo=os baseurl=http://mirrors.163.com/centos/$releasever/os/$basearch/ gpgcheck=1 gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6    #released updates [updates] name=CentOS-$releasever - Updates #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates baseurl=http://mirrors.163.com/centos/$releasever/updates/$basearch/ gpgcheck=1 gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6    #additional packages that may be useful [extras] name=CentOS-$releasever - Extras #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras baseurl=http://mirrors.163.com/centos/$releasever/extras/$basearch/ gpgcheck=1 gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6    #additional packages that extend functionality of existing packages [centosplus] name=CentOS-$releasever - Plus #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus baseurl=http://mirrors.163.com/centos/$releasever/centosplus/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6    #contrib - packages by Centos Users [contrib] name=CentOS-$releasever - Contrib #mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=contrib baseurl=http://mirrors.163.com/centos/$releasever/contrib/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrors.163.com/centos/RPM-GPG-KEY-CentOS-6

[root@bastion-IDC ~]# yum clean all
[root@bastion-IDC ~]# yum makecache          //将服务器上的软件包信息缓存到本地,以提高搜索安装软件的速度
[root@bastion-IDC ~]# yum update              //更新系统

依照上面操作后，yum源就更换成网易的了，并能正常使用。

要特别注意的是：如果要想CentOS使用yum update更新时不升级内核，方法如下：
[root@bastion-IDC ~]# cp /etc/yum.conf /etc/yum.confbak
方法一）修改yum的配置文件
[root@bastion-IDC ~]# vim /etc/yum.conf
在[main]的最后添加 exclude=kernel*

方法二）直接在yum的命令后面加上如下的参数：
[root@bastion-IDC ~]# yum --exclude=kernel* update

---------------------------------------------------------------------------------------------------------------------
如果要更换成阿里云的yum源，只需要将/etc/yum.repos.d/CentOS-Base.repo内容替换成下面内容即可，然后yum clean all、yum makecache、yum update

# 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-6

#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-6

#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-6

#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-6

#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-6

[root@bastion-IDC ~]# yum clean all
[root@bastion-IDC ~]# yum makecache
如果出现下面报错：
https://mirrors.aliyun.com/centos/$releasever/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"

原因分析：
$releasever这个变量在CentOS-Base.repo文件中没有被识别出来。可以去aliyun的镜像官网上查看下正确地址：

即正确地址是：https://mirrors.aliyun.com/centos/6.9/os/x86_64/repodata/repomd.xml
解决办法：将$releasever换成6.9
[root@bastion-IDC ~]# sed -i 's/$releasever/6.9/g' CentOS-Base.repo

==================================================================
如果更换成163的yum源, 出现这种问题, 即"http://mirrors.163.com/centos/6/os/x86_64/repodata/repomd.xml: [Errno 14] PYCURL ERROR 22 - "The requested URL returned error: 404 Not Found"", 解决方法和上面是一样的, 也是到http://mirrors.163.com/centos下查看哪个6.x/os/x86_64/repodata/repomd.xml下存在这个文件, 然后把CentOS-Base.repo文件中的$releasever全部更换为这个6.x即可!

文章来自：https://www.cnblogs.com/kevingrace/p/6252795.html