在 CentOS 7.6 64 位 下执行命令：yum makecache ，报错：There are no enabled repos 的分析解决

1、在 CentOS 7.6 64位 下执行命令：yum makecache ，以更新 yum 源 的缓存，报错：There are no enabled repos，如图1

图1

[root@iZ8vb0tg9av3a17vlbfi28Z ~]# yum makecache
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
There are no enabled repos.
 Run "yum repolist all" to see the repos you have.
 To enable Red Hat Subscription Management repositories:
     subscription-manager repos --enable <repo>
 To enable custom repositories:
     yum-config-manager --enable <repo>

2、决定重新安装 7.6 的 release 包，先到阿里云源的网站，查找到对应的 release 包，复制其链接，如图2

图2

3、依次执行如下命令，如图3

图3

wget https://mirrors.aliyun.com/centos/7.6.1810/os/x86_64/Packages/centos-release-7-6.1810.2.el7.centos.x86_64.rpm
rpm -ivh --replacepkgs --replacefiles centos-release-7-6.1810.2.el7.centos.x86_64.rpm
yum update

4、执行命令：yum makecache ，以更新 yum 源 的缓存，未再报错，符合预期，如图4

图4

[root@iZ8vb0tg9av3a17vlbfi28Z ~]# yum makecache
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
 * base: mirrors.tuna.tsinghua.edu.cn
 * extras: mirrors.huaweicloud.com
 * updates: mirrors.huaweicloud.com
base                                              | 3.6 kB     00:00     
extras                                            | 3.4 kB     00:00     
updates                                           | 3.4 kB     00:00     
(1/8): extras/7/x86_64/prestodelta                  |  47 kB   00:00     
(2/8): extras/7/x86_64/filelists_db                 | 231 kB   00:00     
(3/8): extras/7/x86_64/other_db                     | 118 kB   00:00     
(4/8): updates/7/x86_64/prestodelta                 | 358 kB   00:00     
(5/8): updates/7/x86_64/other_db                    | 351 kB   00:00     
(6/8): updates/7/x86_64/filelists_db                | 2.2 MB   00:00     
(7/8): base/7/x86_64/other_db                       | 2.6 MB   00:00     
(8/8): base/7/x86_64/filelists_db                   | 7.1 MB   00:04     
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