2025年centos 7 亲测可用阿里源
目前这个问题 AI 可回答不上来 ，因为网上说的对的文章太少啦。为防止找不到我，就点个关注吧~
拿阿里云的官网文档来说，centos7是不可用的。
https://mirrors.aliyun.com/repo/Centos-7.repo 这个文件你下载后也是不能用的。会报404，仔细对比后发现，由于CentOS 8操作系统版本结束了生命周期（EOL），Linux社区已不再维护该操作系统版本。所以无论是版本8 还是之前的 7 或者 6,都要使用 centos-vault 源。
而下载得到的Centos-7.repo 文件中是没有配置为 centos-vault 的，并且还要精确写对小版本号，单独的7 目录是不存在的，我们就选用最后一个小版本。
7.0.1406/ - 2015-04-07 22:36
7.1.1503/ - 2015-11-13 21:01
7.2.1511/ - 2016-05-19 00:48
7.3.1611/ - 2017-02-21 06:21
7.4.1708/ - 2018-02-26 22:32
7.5.1804/ - 2018-05-10 04:39
7.6.1810/ - 2018-12-02 22:34
7.7.1908/ - 2019-09-15 09:00
7.8.2003/ - 2020-06-18 01:55
7.9.2009/
所以，总的来说 ，对于版本7来说，CentOS-Base.repo 中必须出现 类似 http://mirrors.aliyun.com/centos-vault/7.9.2009/ 这样的才能正常工作。
写完后你需要打开网址去检查一下，是否可正常访问： https://mirrors.aliyun.com/centos-vault/7.9.2009/
附上Centos 7正常可用的 CentOS-Base.repo 内容：
# 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-7.9.2009 - Base - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/7.9.2009/os/$basearch/
http://mirrors.aliyuncs.com/centos-vault/7.9.2009/os/$basearch/
http://mirrors.cloud.aliyuncs.com/centos-vault/7.9.2009/os/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-7.9.2009 - Updates - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/7.9.2009/updates/$basearch/
http://mirrors.aliyuncs.com/centos-vault/7.9.2009/updates/$basearch/
http://mirrors.cloud.aliyuncs.com/centos-vault/7.9.2009/updates/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-7.9.2009 - Extras - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/7.9.2009/extras/$basearch/
http://mirrors.aliyuncs.com/centos-vault/7.9.2009/extras/$basearch/
http://mirrors.cloud.aliyuncs.com/centos-vault/7.9.2009/extras/$basearch/
gpgcheck=1
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-7.9.2009 - Plus - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/7.9.2009/centosplus/$basearch/
http://mirrors.aliyuncs.com/centos-vault/7.9.2009/centosplus/$basearch/
http://mirrors.cloud.aliyuncs.com/centos-vault/7.9.2009/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
#contrib - packages by Centos Users
[contrib]
name=CentOS-7.9.2009 - Contrib - mirrors.aliyun.com
failovermethod=priority
baseurl=http://mirrors.aliyun.com/centos-vault/7.9.2009/contrib/$basearch/
http://mirrors.aliyuncs.com/centos-vault/7.9.2009/contrib/$basearch/
http://mirrors.cloud.aliyuncs.com/centos-vault/7.9.2009/contrib/$basearch/
gpgcheck=1
enabled=0
gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-7
知道了原理后，centos 6 本质是也是一样的。更改上面的7.9.2009版本为实际存在的版本即克。
而 Centos 8貌似用户比较多，阿里云文档中提供的链接下载后是可以直接使用的 。https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
