[root@Apache ~]# mount /dev/sr0 /mnt/ mount: /dev/sr0 is write-protected, mounting read-only [root@Apache ~]# ls /mnt/ CentOS_BuildTag EFI EULA GPL images isolinux LiveOS Packages repodata RPM-GPG-KEY-CentOS-7 RPM-GPG-KEY-CentOS-Testing-7 TRANS.TBL [root@Apache ~]# vim /etc/yum.repos.d/yum.repo [server] name= server baseurl=file:///mnt gpgcheck=0 enable=1 [root@Apache ~]# yum clean all Loaded plugins: fastestmirror, product-id, search-disabled-repos, subscription-manager This system is not registered with an entitlement server. You can use subscription-manager to register. Cleaning repos: server Cleaning up everything Maybe you want: rm -rf /var/cache/yum, to also free up space taken by orphaned data from disabled or removed repos Cleaning up list of fastest mirrors [root@Apache ~]# yum repolist Loaded plugins: fastestmirror, product-id, search-disabled-repos, subscription-manager This system is not registered with an entitlement server. You can use subscription-man