yum報錯：Error: requested datatype primary not available

[root@king ~]# yum repolist

Loaded plugins: product-id, refresh-packagekit, security, subscription-manager

This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.

base                                                                                         |  224 B     00:00     

Error: requested datatype primary not available

步驟：

yum clean all

yum --rebuilddb